diff --git a/components/Blueprints/class-runner.php b/components/Blueprints/class-runner.php
index e7f563de..4d7ab908 100644
--- a/components/Blueprints/class-runner.php
+++ b/components/Blueprints/class-runner.php
@@ -55,7 +55,7 @@
 use WordPress\HttpClient\Client;
 use WordPress\Zip\ZipFilesystem;
 
-use function WordPress\Encoding\utf8_is_valid_byte_stream;
+use function WordPress\Encoding\_wp_has_noncharacters_fallback;
 use function WordPress\Filesystem\wp_unix_sys_get_temp_dir;
 use function WordPress\Zip\is_zip_file_stream;
 
@@ -383,7 +383,7 @@ private function load_blueprint() {
 		if ( function_exists( 'mb_check_encoding' ) ) {
 			$is_valid_utf8 = mb_check_encoding( $blueprint_string, 'UTF-8' );
 		} else {
-			$is_valid_utf8 = utf8_is_valid_byte_stream( $blueprint_string );
+			$is_valid_utf8 = ! _wp_has_noncharacters_fallback( $blueprint_string );
 		}
 
 		if ( ! $is_valid_utf8 ) {
diff --git a/components/DataLiberation/Tests/CSSTokenizerTest.php b/components/DataLiberation/Tests/CSSTokenizerTest.php
new file mode 100644
index 00000000..1c568c2a
--- /dev/null
+++ b/components/DataLiberation/Tests/CSSTokenizerTest.php
@@ -0,0 +1,1330 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use WordPress\DataLiberation\URL\CSSTokenizer;
+
+/**
+ * Comprehensive CSS tokenizer tests based on the CSS Syntax Level 3 specification.
+ */
+class CSSTokenizerTest extends TestCase {
+
+	/**
+	 * Tests that the tokenizer produces the expected tokens for all test cases.
+	 *
+	 * @dataProvider corpus_provider
+	 */
+	public function test_tokenizer_matches_spec( string $css, array $expected_tokens ): void {
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor );
+		$this->assertSame( $expected_tokens, $actual_tokens );
+	}
+
+	/**
+	 * Provides the test cases from the @rmenke/css-tokenizer-test test corpus.
+	 *
+	 * @see https://github.com/romainmenke/css-tokenizer-tests/
+	 * @return array
+	 */
+	static public function corpus_provider(): array {
+		return json_decode(file_get_contents(__DIR__ . '/css-test-cases.json'), true);
+	}
+
+	/**
+	 * Collects all tokens from a CSS processor into an array.
+	 *
+	 * @param CSSTokenizer $processor The CSS processor.
+	 * @return array Array of tokens with type, raw, startIndex, endIndex, structured.
+	 */
+	static public function collect_tokens( CSSTokenizer $processor, $keys = null ): array {
+		$tokens = array();
+
+		while ( $processor->next_token() ) {
+			$type = $processor->get_token_type();
+
+			$byte_start = $processor->get_token_start();
+			$byte_end   = $byte_start + $processor->get_token_length();
+
+			$token = array(
+				'type'       => $type,
+				'raw'        => $processor->get_unnormalized_token(),
+				'startIndex' => $byte_start,
+				'endIndex'   => $byte_end,
+				'normalized' => $processor->get_normalized_token(),
+				'value'      => $processor->get_token_value(),
+			);
+			if ( null !== $processor->get_token_unit() ) {
+				$token['unit'] = $processor->get_token_unit();
+			}
+
+			if ( null !== $keys ) {
+				$token = array_intersect_key( $token, array_flip( $keys ) );
+			}
+
+			$tokens[] = $token;
+		}
+
+		return $tokens;
+	}
+
+	/**
+	 * Tests handling of non-UTF-8 byte sequences in identifiers.
+	 * 
+	 * Invalid UTF-8 sequences should be replaced with U+FFFD replacement characters
+	 * during tokenization, allowing the CSS to continue processing.
+	 */
+	public function test_non_utf8_sequences_in_identifiers(): void {
+		// Invalid UTF-8 sequence 0xC0 0x80 (overlong encoding).
+		$css = ".class\xF1name";
+
+		$expected = array(
+			// .class�name (0xF1 replaced with U+FFFD).
+			array(
+				'type' => CSSTokenizer::TOKEN_DELIM,
+				'raw'  => '.',
+				'normalized' => '.',
+				'value' => '.',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => "class\xF1name",
+				'normalized' => 'class�name',
+				'value' => 'class�name',
+			),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value', 'unit'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+
+	public function test_invalid_utf8_with_valid_prefix_in_identifiers(): void {
+		// Invalid 2-byte prefix is replaced with a single U+FFFD.
+		$css = ".test\xE2\x80name";
+
+		$expected = array(
+			array(
+				'type' => CSSTokenizer::TOKEN_DELIM,
+				'raw'  => '.',
+				'normalized' => '.',
+				'value' => '.',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => "test\xE2\x80name",
+				'normalized' => 'test�name',
+				'value' => 'test�name',
+			),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+
+	public function test_invalid_utf8_with_two_single_byte_invalid_sequences(): void {
+		// Two distinct single byte invalid sequences are replaced with
+		// two separate U+FFFD replacement characters.
+		$css = ".test\xE2\xE2name";
+
+		$expected = array(
+			array(
+				'type' => CSSTokenizer::TOKEN_DELIM,
+				'raw'  => '.',
+				'normalized' => '.',
+				'value' => '.',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => "test\xE2\xE2name",
+				'normalized' => 'test��name',
+				'value' => 'test��name',
+			),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+
+	/**
+	 * Legacy test to ensure basic tokenization still works.
+	 */
+	public function test_tokenize_labels_core_tokens(): void {
+		$css = <<<CSS
+@media screen and (min-width: 10px) {
+	background: url("/images/a.png");
+}
+CSS;
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_AT_KEYWORD, 'raw' => '@media' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT, 'raw' => 'screen' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT, 'raw' => 'and' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_PAREN, 'raw' => '(' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT, 'raw' => 'min-width' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON, 'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION, 'raw' => '10px' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN, 'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE, 'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => "\n\t" ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT, 'raw' => 'background' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON, 'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION, 'raw' => 'url(' ),
+			array( 'type' => CSSTokenizer::TOKEN_STRING, 'raw' => '"/images/a.png"' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN, 'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON, 'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE, 'raw' => "\n" ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE, 'raw' => '}' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of complex selectors with pseudo-classes.
+	 */
+	public function test_complex_selector_with_pseudo_classes(): void {
+		$css = 'a:hover::before, div.class#id:not(.disabled)';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'a' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'hover' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'before' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'div' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '.' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'class' ),
+			array( 'type' => CSSTokenizer::TOKEN_HASH,         'raw' => '#id' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'not(' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '.' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'disabled' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of CSS comments.
+	 */
+	public function test_css_comments(): void {
+		$css = '/* This is a comment */ .class { color: red; /* Another comment */ }';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_COMMENT,      'raw' => '/* This is a comment */' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '.' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'class' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE,   'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'red' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMENT,      'raw' => '/* Another comment */' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,  'raw' => '}' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of media queries.
+	 */
+	public function test_media_query(): void {
+		$css = '@media screen and (min-width: 768px) and (max-width: 1024px)';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_AT_KEYWORD,   'raw' => '@media' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'screen' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'and' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_PAREN,   'raw' => '(' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'min-width' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '768px' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'and' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_PAREN,   'raw' => '(' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'max-width' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '1024px' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of keyframes animation.
+	 */
+	public function test_keyframes_animation(): void {
+		$css = '@keyframes slide-in { 0% { opacity: 0; } 100% { opacity: 1; } }';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_AT_KEYWORD,   'raw' => '@keyframes' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'slide-in' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE,   'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_PERCENTAGE,   'raw' => '0%' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE,   'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'opacity' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,  'raw' => '}' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_PERCENTAGE,   'raw' => '100%' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE,   'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'opacity' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '1' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,  'raw' => '}' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,  'raw' => '}' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of vendor-prefixed properties.
+	 */
+	public function test_vendor_prefixed_properties(): void {
+		$css = '-webkit-transform: rotate(45deg); -moz-border-radius: 5px;';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => '-webkit-transform' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'rotate(' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '45deg' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => '-moz-border-radius' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '5px' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of attribute selectors.
+	 */
+	public function test_attribute_selectors(): void {
+		$css = 'input[type="text"][required], a[href^="https://"]';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,         'raw' => 'input' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACKET,  'raw' => '[' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,         'raw' => 'type' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,         'raw' => '=' ),
+			array( 'type' => CSSTokenizer::TOKEN_STRING,        'raw' => '"text"' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACKET, 'raw' => ']' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACKET,  'raw' => '[' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,         'raw' => 'required' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACKET, 'raw' => ']' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,         'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,    'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,         'raw' => 'a' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACKET,  'raw' => '[' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,         'raw' => 'href' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,         'raw' => '^' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,         'raw' => '=' ),
+			array( 'type' => CSSTokenizer::TOKEN_STRING,        'raw' => '"https://"' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACKET, 'raw' => ']' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of calc() function with complex expressions.
+	 */
+	public function test_calc_function(): void {
+		$css = 'width: calc(100% - 20px * 2 + 5em);';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'width' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'calc(' ),
+			array( 'type' => CSSTokenizer::TOKEN_PERCENTAGE,   'raw' => '100%' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '-' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '20px' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '*' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '2' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '+' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '5em' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of RGB/RGBA color functions.
+	 */
+	public function test_color_functions(): void {
+		$css = 'color: rgb(255, 128, 0); background: rgba(0, 0, 0, 0.5);';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'rgb(' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '255' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '128' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'background' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'rgba(' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '0.5' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of CSS custom properties (variables).
+	 */
+	public function test_css_variables(): void {
+		$css = '--main-color: #ff0000; color: var(--main-color);';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => '--main-color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_HASH,         'raw' => '#ff0000' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'var(' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => '--main-color' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of gradient functions.
+	 */
+	public function test_gradient_functions(): void {
+		$css = 'background: linear-gradient(to right, red 0%, blue 100%);';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'background' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'linear-gradient(' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'to' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'right' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'red' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_PERCENTAGE,   'raw' => '0%' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'blue' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_PERCENTAGE,   'raw' => '100%' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of grid layout properties.
+	 */
+	public function test_grid_layout(): void {
+		$css = 'grid-template-columns: repeat(3, 1fr); gap: 10px 20px;';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'grid-template-columns' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'repeat(' ),
+			array( 'type' => CSSTokenizer::TOKEN_NUMBER,       'raw' => '3' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '1fr' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'gap' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '10px' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '20px' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of URL functions with various formats.
+	 */
+	public function test_url_formats(): void {
+		$css = 'background: url("image.png"), url(\'font.woff\'), url(https://example.com/bg.jpg);';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'background' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'url(' ),
+			array( 'type' => CSSTokenizer::TOKEN_STRING,       'raw' => '"image.png"' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_FUNCTION,     'raw' => 'url(' ),
+			array( 'type' => CSSTokenizer::TOKEN_STRING,       'raw' => "'font.woff'" ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,  'raw' => ')' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_URL,          'raw' => 'url(https://example.com/bg.jpg)' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of !important declarations.
+	 */
+	public function test_important_declarations(): void {
+		$css = 'color: red !important; margin: 0px !important;';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'red' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '!' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'important' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'margin' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DIMENSION,    'raw' => '0px' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '!' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'important' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of multiple selectors with combinators.
+	 */
+	public function test_complex_combinators(): void {
+		$css = 'div > p + span ~ a.link';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'div' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '>' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'p' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '+' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'span' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '~' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'a' ),
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '.' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'link' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests tokenization of escaped characters in identifiers.
+	 */
+	public function test_escaped_identifiers(): void {
+		$css = '.class\\:name, #id\\@special { color: blue; }';
+
+		$expected = array(
+			array( 'type' => CSSTokenizer::TOKEN_DELIM,        'raw' => '.' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'class\\:name' ),
+			array( 'type' => CSSTokenizer::TOKEN_COMMA,        'raw' => ',' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_HASH,         'raw' => '#id\\@special' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_LEFT_BRACE,   'raw' => '{' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'color' ),
+			array( 'type' => CSSTokenizer::TOKEN_COLON,        'raw' => ':' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_IDENT,        'raw' => 'blue' ),
+			array( 'type' => CSSTokenizer::TOKEN_SEMICOLON,    'raw' => ';' ),
+			array( 'type' => CSSTokenizer::TOKEN_WHITESPACE,   'raw' => ' ' ),
+			array( 'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,  'raw' => '}' ),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw'] );
+		$this->assertSame( $actual_tokens, $expected );
+	}
+
+	/**
+	 * Tests that get_normalized_token() applies CSS normalization.
+	 *
+	 * Uses a comprehensive CSS selector with rules that includes:
+	 * - CSS escapes in class names and IDs
+	 * - URLs with escape sequences
+	 * - String values with escapes and line endings
+	 * - Comments with various line ending characters
+	 * - Null bytes in identifiers
+	 * - Mixed line endings (\r\n, \r, \f) that need normalization
+	 */
+	public function test_get_normalized_token_applies_normalization(): void {
+		// Comprehensive CSS with normalization requirements.
+		$css = "/* Comment\r\nwith\flines */\r\n" .
+		       ".c\\6c ass.n\\61 me\r#id\\@value\r\n{\r\n" .
+		       "\tbackground:\furl(path\\2f to\\2f image.png);\r\n" .
+		       "\tcontent:\r\"text\\A string\";\r\n" .
+		       "}";
+
+		$expected = array(
+			// Comment with \r\n and \f.
+			array(
+				'type'       => CSSTokenizer::TOKEN_COMMENT,
+				'raw'        => "/* Comment\r\nwith\flines */",
+				'normalized' => "/* Comment\nwith\nlines */",
+				'value'      => null,
+			),
+			// Whitespace with \r\n.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r\n",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// Class selector delimiter.
+			array(
+				'type'       => CSSTokenizer::TOKEN_DELIM,
+				'raw'        => '.',
+				'normalized' => '.',
+				'value'      => '.',
+			),
+			// Class name with escape (\6c = 'l'), space gets consumed by escape.
+			array(
+				'type'       => CSSTokenizer::TOKEN_IDENT,
+				'raw'        => 'c\\6c ass',
+				'normalized' => 'class', // Escapes decoded.
+				'value'      => 'class', // Decoded: \6c → l, space consumed.
+			),
+			// Delimiter.
+			array(
+				'type'       => CSSTokenizer::TOKEN_DELIM,
+				'raw'        => '.',
+				'normalized' => '.',
+				'value'      => '.',
+			),
+			// Identifier with escape (\61 = 'a'), space gets consumed.
+			array(
+				'type'       => CSSTokenizer::TOKEN_IDENT,
+				'raw'        => 'n\\61 me',
+				'normalized' => 'name', // Escapes decoded.
+				'value'      => 'name', // Decoded: \61 → a, space consumed.
+			),
+			// Whitespace with \r.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// ID selector with escape.
+			array(
+				'type'       => CSSTokenizer::TOKEN_HASH,
+				'raw'        => '#id\\@value',
+				'normalized' => '#id@value', // Escapes decoded.
+				'value'      => 'id@value', // Decoded value.
+			),
+			// Whitespace with \r\n.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r\n",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// Opening brace.
+			array(
+				'type'       => CSSTokenizer::TOKEN_LEFT_BRACE,
+				'raw'        => '{',
+				'normalized' => '{',
+				'value'      => null,
+			),
+			// Whitespace with \r\n and tab (consumed together).
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r\n\t",
+				'normalized' => "\n\t",
+				'value'      => null,
+			),
+			array(
+				'type'       => CSSTokenizer::TOKEN_IDENT,
+				'raw'        => 'background',
+				'normalized' => 'background',
+				'value'      => 'background',
+			),
+			// Colon.
+			array(
+				'type'       => CSSTokenizer::TOKEN_COLON,
+				'raw'        => ':',
+				'normalized' => ':',
+				'value'      => null,
+			),
+			// Whitespace with \f.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\f",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// URL token with escapes (entire url(...) is one token).
+			array(
+				'type'       => CSSTokenizer::TOKEN_URL,
+				'raw'        => 'url(path\\2f to\\2f image.png)',
+				'normalized' => 'url(path/to/image.png)', // Escapes decoded.
+				'value'      => 'path/to/image.png', // Decoded: \2f → /, spaces consumed.
+			),
+			// Semicolon.
+			array(
+				'type'       => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'        => ';',
+				'normalized' => ';',
+				'value'      => null,
+			),
+			// Whitespace with \r\n and tab (consumed together).
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r\n\t",
+				'normalized' => "\n\t",
+				'value'      => null,
+			),
+			array(
+				'type'       => CSSTokenizer::TOKEN_IDENT,
+				'raw'        => 'content',
+				'normalized' => 'content',
+				'value'      => 'content',
+			),
+			// Colon.
+			array(
+				'type'       => CSSTokenizer::TOKEN_COLON,
+				'raw'        => ':',
+				'normalized' => ':',
+				'value'      => null,
+			),
+			// Whitespace with \r.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// String with escape (\A = newline, space consumed).
+			array(
+				'type'       => CSSTokenizer::TOKEN_STRING,
+				'raw'        => '"text\\A string"',
+				'normalized' => "\"text\nstring\"", // Escapes decoded, quotes preserved.
+				'value'      => "text\nstring", // \A → \n, space consumed.
+			),
+			// Semicolon.
+			array(
+				'type'       => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'        => ';',
+				'normalized' => ';',
+				'value'      => null,
+			),
+			// Whitespace with \r\n.
+			array(
+				'type'       => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'        => "\r\n",
+				'normalized' => "\n",
+				'value'      => null,
+			),
+			// Closing brace.
+			array(
+				'type'       => CSSTokenizer::TOKEN_RIGHT_BRACE,
+				'raw'        => '}',
+				'normalized' => '}',
+				'value'      => null,
+			),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+
+	public function test_dimension_token_value(): void {
+		$css = '10px;15em;20%;30pt;40pc;50vw;';
+		$expected = array(
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw' => '10px',
+				'normalized' => '10px',
+				'value' => '10',
+				'unit' => 'px',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw' => '15em',
+				'normalized' => '15em',
+				'value' => '15',
+				'unit' => 'em',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_PERCENTAGE,
+				'raw' => '20%',
+				'normalized' => '20%',
+				'value' => '20',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw' => '30pt',
+				'normalized' => '30pt',
+				'value' => '30',
+				'unit' => 'pt',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw' => '40pc',
+				'normalized' => '40pc',
+				'value' => '40',
+				'unit' => 'pc',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw' => '50vw',
+				'normalized' => '50vw',
+				'value' => '50',
+				'unit' => 'vw',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw' => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+		);
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value', 'unit'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+
+	/**
+	 * Tests that create() validates encoding and only accepts UTF-8.
+	 */
+	public function test_create_validates_encoding(): void {
+		// UTF-8 encoding should work (default).
+		$tokenizer = CSSTokenizer::create( '.class { color: red; }' );
+		$this->assertInstanceOf( CSSTokenizer::class, $tokenizer );
+
+		// UTF-8 encoding should work (explicit).
+		$tokenizer = CSSTokenizer::create( '.class { color: red; }', 'UTF-8' );
+		$this->assertInstanceOf( CSSTokenizer::class, $tokenizer );
+
+		// Other encodings should return null.
+		$tokenizer = CSSTokenizer::create( '.class { color: red; }', 'ISO-8859-1' );
+		$this->assertNull( $tokenizer );
+
+		$tokenizer = CSSTokenizer::create( '.class { color: red; }', 'Windows-1252' );
+		$this->assertNull( $tokenizer );
+	}
+
+	/**
+	 * Tests escape sequences in unusual and edge-case positions.
+	 *
+	 * Covers:
+	 * - Multiple consecutive escapes
+	 * - Escapes in function names
+	 * - Escapes in at-keywords
+	 * - Escapes in dimension units
+	 * - Null byte escapes (\0)
+	 * - Escaped special characters (@, #, !, etc.)
+	 * - Escaped whitespace that gets consumed by the escape
+	 * - Unicode escapes for various characters
+	 */
+	public function test_escape_sequences_in_unusual_places() {
+		// Complex CSS with escapes in many unusual but valid positions
+		$css = '@\\6D edia ' .                           // @media with \6D (m) and space consumed
+		       '\\73 creen ' .                           // screen with \73 (s) and space consumed
+		       '{' .
+		       ' .\\63 l\\61 ss\\5F name ' .             // .class_name with escapes and spaces consumed
+		       "#\\69 d\\5C 0test\x00 " .                // #id\0test with null byte escape (should be preserved)
+			                                             // AND an actual null byte (should be replaced with a U+FFFD REPLACEMENT CHARACTER)
+		       '{' .
+		       ' c\\6F lor: ' .                          // color: with \6F (o) and space consumed
+		       'r\\65 d ' .                              // red with escape
+		       '\\21 important;' .                       // !important with escaped !
+		       ' w\\69 dth: ' .                          // width:
+		       '10\\70 x;' .                             // 10px (dimension with escaped unit)
+		       ' background: ' .
+		       '\\75 rl(' .                              // url( with escaped u
+		       '"p\\61 th\\2F img\\2E png"' .            // "path/img.png" with escapes
+		       ');' .
+		       ' content: "\\5C \\5C ";' .               // "\\ \\" - escaped backslashes
+		       ' font-family: \\22 Arial\\22 ;' .       // "Arial" with escaped quotes
+		       ' }' .
+		       '}';
+
+		$expected = array(
+			// @\6D edia -> @media
+			array(
+				'type' => CSSTokenizer::TOKEN_AT_KEYWORD,
+				'raw'  => '@\\6D edia',
+				'normalized' => '@media',
+				'value' => 'media',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// \73 creen -> screen
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => '\\73 creen',
+				'normalized' => 'screen',
+				'value' => 'screen',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_LEFT_BRACE,
+				'raw'  => '{',
+				'normalized' => '{',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// Delimiter .
+			array(
+				'type' => CSSTokenizer::TOKEN_DELIM,
+				'raw'  => '.',
+				'normalized' => '.',
+				'value' => '.',
+			),
+			// \63 l\61 ss\5F name -> class_name
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => '\\63 l\\61 ss\\5F name',
+				'normalized' => 'class_name',
+				'value' => 'class_name',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// #\69 d\5C 0test -> #id\0test (with encoded null byte)
+			array(
+				'type' => CSSTokenizer::TOKEN_HASH,
+				'raw'  => "#\\69 d\\5C 0test\x00",
+				'normalized' => "#id\\0test�",
+				// Ensure the value is normalized.
+				'value' => "id\\0test�",
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_LEFT_BRACE,
+				'raw'  => '{',
+				'normalized' => '{',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// c\6F lor -> color
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'c\\6F lor',
+				'normalized' => 'color',
+				'value' => 'color',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_COLON,
+				'raw'  => ':',
+				'normalized' => ':',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// r\65 d -> red
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'r\\65 d',
+				'normalized' => 'red',
+				'value' => 'red',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// \21 important -> !important (single identifier with escaped !)
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => '\\21 important',
+				'normalized' => '!important',
+				'value' => '!important',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'  => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// w\69 dth -> width
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'w\\69 dth',
+				'normalized' => 'width',
+				'value' => 'width',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_COLON,
+				'raw'  => ':',
+				'normalized' => ':',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// 10\70 x -> 10px (dimension with escaped unit)
+			array(
+				'type' => CSSTokenizer::TOKEN_DIMENSION,
+				'raw'  => '10\\70 x',
+				'normalized' => '10px',
+				'value' => '10',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'  => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'background',
+				'normalized' => 'background',
+				'value' => 'background',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_COLON,
+				'raw'  => ':',
+				'normalized' => ':',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// \75 rl( -> url( (escaped function name)
+			array(
+				'type' => CSSTokenizer::TOKEN_FUNCTION,
+				'raw'  => '\\75 rl(',
+				'normalized' => 'url(',
+				'value' => 'url',
+			),
+			// String with escapes: "p\61 th\2F img\2E png"
+			array(
+				'type' => CSSTokenizer::TOKEN_STRING,
+				'raw'  => '"p\\61 th\\2F img\\2E png"',
+				'normalized' => '"path/img.png"',
+				'value' => 'path/img.png',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_RIGHT_PAREN,
+				'raw'  => ')',
+				'normalized' => ')',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'  => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'content',
+				'normalized' => 'content',
+				'value' => 'content',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_COLON,
+				'raw'  => ':',
+				'normalized' => ':',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// String with escaped backslashes: "\5C \5C " -> "\\"
+			// Each \5C sequence (with trailing space consumed) becomes one backslash
+			array(
+				'type' => CSSTokenizer::TOKEN_STRING,
+				'raw'  => '"\\5C \\5C "',
+				'normalized' => '"\\\\"',
+				'value' => '\\\\',  // Two backslashes total
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'  => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => 'font-family',
+				'normalized' => 'font-family',
+				'value' => 'font-family',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_COLON,
+				'raw'  => ':',
+				'normalized' => ':',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			// \22 Arial\22 -> "Arial" (escaped quotes make it an ident)
+			array(
+				'type' => CSSTokenizer::TOKEN_IDENT,
+				'raw'  => '\\22 Arial\\22 ',
+				'normalized' => '"Arial"',
+				'value' => '"Arial"',
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_SEMICOLON,
+				'raw'  => ';',
+				'normalized' => ';',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_WHITESPACE,
+				'raw'  => ' ',
+				'normalized' => ' ',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,
+				'raw'  => '}',
+				'normalized' => '}',
+				'value' => null,
+			),
+			array(
+				'type' => CSSTokenizer::TOKEN_RIGHT_BRACE,
+				'raw'  => '}',
+				'normalized' => '}',
+				'value' => null,
+			),
+		);
+
+		$processor = CSSTokenizer::create( $css );
+		$actual_tokens = $this->collect_tokens( $processor, ['type', 'raw', 'normalized', 'value'] );
+		$this->assertSame( $expected, $actual_tokens );
+	}
+}
diff --git a/components/DataLiberation/Tests/css-test-cases.json b/components/DataLiberation/Tests/css-test-cases.json
new file mode 100644
index 00000000..a1c10081
--- /dev/null
+++ b/components/DataLiberation/Tests/css-test-cases.json
@@ -0,0 +1,4923 @@
+{
+	"tests/at-keyword/0001": {
+		"css": "@foo\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@foo",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "@foo",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0002": {
+		"css": "@--\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@--",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "@--",
+				"value": "--"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0003": {
+		"css": "@-1\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "@",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "@",
+				"value": "@"
+			},
+			{
+				"type": "number-token",
+				"raw": "-1",
+				"startIndex": 1,
+				"endIndex": 3,
+				"normalized": "-1",
+				"value": "-1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0004": {
+		"css": "@--1\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@--1",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "@--1",
+				"value": "--1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0005": {
+		"css": "@\\@\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@\\@",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "@@",
+				"value": "@"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0006": {
+		"css": "@_\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@_",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "@_",
+				"value": "_"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0007": {
+		"css": "@\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "@",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "@",
+				"value": "@"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0008": {
+		"css": "pvA3@\\\neBnP\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "pvA3",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "pvA3",
+				"value": "pvA3"
+			},
+			{
+				"type": "delim-token",
+				"raw": "@",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "@",
+				"value": "@"
+			},
+			{
+				"type": "delim-token",
+				"raw": "\\",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\\",
+				"value": "\\"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "eBnP",
+				"startIndex": 7,
+				"endIndex": 11,
+				"normalized": "eBnP",
+				"value": "eBnP"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/at-keyword/0009": {
+		"css": "@aa𐀀\n",
+		"tokens": [
+			{
+				"type": "at-keyword-token",
+				"raw": "@aa𐀀",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "@aa𐀀",
+				"value": "aa𐀀"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-string/0001": {
+		"css": "\"foo\n\"\n",
+		"tokens": [
+			{
+				"type": "bad-string-token",
+				"raw": "\"foo",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "\"foo",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "bad-string-token",
+				"raw": "\"",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\"",
+				"value": ""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-string/0002": {
+		"css": "\"foo\\\n\"\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"foo\\\n\"",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "\"foo\\\n\"",
+				"value": "foo\\\n"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-string/0003": {
+		"css": "\"foo\r\n\"\n",
+		"tokens": [
+			{
+				"type": "bad-string-token",
+				"raw": "\"foo",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "\"foo",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\r\n",
+				"startIndex": 4,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "bad-string-token",
+				"raw": "\"",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\"",
+				"value": ""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-string/0004": {
+		"css": "\"foo\\\r\n\"\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"foo\\\r\n\"",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "\"foo\\\n\"",
+				"value": "foo\\\n"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-string/0005": {
+		"css": "\"aa𐀀\n",
+		"tokens": [
+			{
+				"type": "bad-string-token",
+				"raw": "\"aa𐀀",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "\"aa𐀀",
+				"value": "aa𐀀"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0001": {
+		"css": "url(\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(\n",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "url(\n",
+				"value": ""
+			}
+		]
+	},
+	"tests/bad-url/0002": {
+		"css": "url( a\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( a\n",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "url( a\n",
+				"value": "a"
+			}
+		]
+	},
+	"tests/bad-url/0003": {
+		"css": "url( a a\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url( a a\n",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "url( a a\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0004": {
+		"css": "url( a a)\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url( a a)",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "url( a a)",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0005": {
+		"css": "url( a a\\)\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url( a a\\)\n",
+				"startIndex": 0,
+				"endIndex": 11,
+				"normalized": "url( a a)\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0006": {
+		"css": "url( \\\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url( \\\n",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "url( \\\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0007": {
+		"css": "url(a'')\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url(a'')",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "url(a'')",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/bad-url/0008": {
+		"css": "url(a\")\n",
+		"tokens": [
+			{
+				"type": "bad-url-token",
+				"raw": "url(a\")",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "url(a\")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/colon/0001": {
+		"css": ":\n",
+		"tokens": [
+			{
+				"type": "colon-token",
+				"raw": ":",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ":",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/comma/0001": {
+		"css": ",\n",
+		"tokens": [
+			{
+				"type": "comma-token",
+				"raw": ",",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ",",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0001": {
+		"css": "/* a comment */\n",
+		"tokens": [
+			{
+				"type": "comment",
+				"raw": "/* a comment */",
+				"startIndex": 0,
+				"endIndex": 15,
+				"normalized": "/* a comment */",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 15,
+				"endIndex": 16,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0002": {
+		"css": "/* a comment ",
+		"tokens": [
+			{
+				"type": "comment",
+				"raw": "/* a comment ",
+				"startIndex": 0,
+				"endIndex": 13,
+				"normalized": "/* a comment ",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0003": {
+		"css": "a/**/b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "a",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": "comment",
+				"raw": "/**/",
+				"startIndex": 1,
+				"endIndex": 5,
+				"normalized": "/**/",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "b",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "b",
+				"value": "b"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0004": {
+		"css": "/*\\*/*/\n",
+		"tokens": [
+			{
+				"type": "comment",
+				"raw": "/*\\*/",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "/**/",
+				"value": null
+			},
+			{
+				"type": "delim-token",
+				"raw": "*",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "*",
+				"value": "*"
+			},
+			{
+				"type": "delim-token",
+				"raw": "/",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "/",
+				"value": "/"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0005": {
+		"css": "/* a comment *",
+		"tokens": [
+			{
+				"type": "comment",
+				"raw": "/* a comment *",
+				"startIndex": 0,
+				"endIndex": 14,
+				"normalized": "/* a comment *",
+				"value": null
+			}
+		]
+	},
+	"tests/comment/0006": {
+		"css": "/*a𐀀*/\n",
+		"tokens": [
+			{
+				"type": "comment",
+				"raw": "/*a𐀀*/",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "/*a𐀀*/",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/digit/0001": {
+		"css": "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "0",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "0",
+				"value": "0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "1",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "1",
+				"value": "1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "2",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "2",
+				"value": "2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "3",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "3",
+				"value": "3"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "4",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "4",
+				"value": "4"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "5",
+				"startIndex": 10,
+				"endIndex": 11,
+				"normalized": "5",
+				"value": "5"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "6",
+				"startIndex": 12,
+				"endIndex": 13,
+				"normalized": "6",
+				"value": "6"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 13,
+				"endIndex": 14,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "7",
+				"startIndex": 14,
+				"endIndex": 15,
+				"normalized": "7",
+				"value": "7"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 15,
+				"endIndex": 16,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "8",
+				"startIndex": 16,
+				"endIndex": 17,
+				"normalized": "8",
+				"value": "8"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 17,
+				"endIndex": 18,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "9",
+				"startIndex": 18,
+				"endIndex": 19,
+				"normalized": "9",
+				"value": "9"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 19,
+				"endIndex": 20,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0001": {
+		"css": "10px\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10px",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "10px",
+				"value": "10",
+				"unit": "px"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0002": {
+		"css": "10\\70 x\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10\\70 x",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "10px",
+				"value": "10",
+				"unit": "px"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0003": {
+		"css": "10--custom-px\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10--custom-px",
+				"startIndex": 0,
+				"endIndex": 13,
+				"normalized": "10--custom-px",
+				"value": "10",
+				"unit": "--custom-px"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 13,
+				"endIndex": 14,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0004": {
+		"css": "10e2px\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10e2px",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "10e2px",
+				"value": "10e2",
+				"unit": "px"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0005": {
+		"css": "10E2PX\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10E2PX",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "10E2PX",
+				"value": "10E2",
+				"unit": "PX"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0006": {
+		"css": "10\\0\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10\\0\n",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "10�",
+				"value": "10",
+				"unit": "�"
+			}
+		]
+	},
+	"tests/dimension/0007": {
+		"css": "10a𐀀\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10a𐀀",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "10a𐀀",
+				"value": "10",
+				"unit": "a𐀀"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/dimension/0008": {
+		"css": "10a\u0000",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "10a\u0000",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "10a�",
+				"value": "10",
+				"unit": "a�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0001": {
+		"css": "\\",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0002": {
+		"css": "\\0",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\0",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0003": {
+		"css": "\\\\",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\\\",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "\\",
+				"value": "\\"
+			}
+		]
+	},
+	"tests/escaped-code-point/0004": {
+		"css": "\\0a b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\0a b",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "\nb",
+				"value": "\nb"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0005": {
+		"css": "\\0ab \n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\0ab ",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "«",
+				"value": "«"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0006": {
+		"css": "\\0ab (foo)\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "\\0ab (",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "«(",
+				"value": "«"
+			},
+			{
+				"type": "ident-token",
+				"raw": "foo",
+				"startIndex": 6,
+				"endIndex": 9,
+				"normalized": "foo",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 10,
+				"endIndex": 11,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0007": {
+		"css": "\\0ab  (foo)\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\0ab ",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "«",
+				"value": "«"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": " ",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": " ",
+				"value": null
+			},
+			{
+				"type": "(-token",
+				"raw": "(",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "(",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "foo",
+				"startIndex": 7,
+				"endIndex": 10,
+				"normalized": "foo",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 10,
+				"endIndex": 11,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0008": {
+		"css": "\\0000ab\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\0000ab\n",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "«",
+				"value": "«"
+			}
+		]
+	},
+	"tests/escaped-code-point/0009": {
+		"css": "\\00000ab\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\00000ab",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "\nb",
+				"value": "\nb"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0010": {
+		"css": "\\110000\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\110000\n",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0011": {
+		"css": "\\00D800\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\00D800\n",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0012": {
+		"css": "\\00DFFF\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\00DFFF\n",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/escaped-code-point/0013": {
+		"css": "\\\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "\\",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "\\",
+				"value": "\\"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0014": {
+		"css": "\\\u0000\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\\u0000",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "�",
+				"value": "�"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0015": {
+		"css": "\\\u0000\b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\\u0000",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "�",
+				"value": "�"
+			},
+			{
+				"type": "delim-token",
+				"raw": "\b",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\b",
+				"value": "\b"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/escaped-code-point/0016": {
+		"css": "\"a\\12\r\nb\"",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"a\\12\r\nb\"",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "\"a\u0012b\"",
+				"value": "a\u0012b"
+			}
+		]
+	},
+	"tests/full-stop/0001": {
+		"css": ".\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": ".",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ".",
+				"value": "."
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/full-stop/0002": {
+		"css": ".a\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": ".",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ".",
+				"value": "."
+			},
+			{
+				"type": "ident-token",
+				"raw": "a",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/full-stop/0003": {
+		"css": ".1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": ".1",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": ".1",
+				"value": ".1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/fuzz/01a166c0-ca20-43a5-9ab0-0984e4a5362b": {
+		"css": "4waPtwEEGH\\\u0000jV3zM6hh6w30N0PC 7m8KM0HcWGOPw28Gt(r19",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "4waPtwEEGH\\\u0000jV3zM6hh6w30N0PC",
+				"startIndex": 0,
+				"endIndex": 28,
+				"normalized": "4waPtwEEGH�jV3zM6hh6w30N0PC",
+				"value": "4",
+				"unit": "waPtwEEGH�jV3zM6hh6w30N0PC"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": " ",
+				"startIndex": 28,
+				"endIndex": 29,
+				"normalized": " ",
+				"value": null
+			},
+			{
+				"type": "dimension-token",
+				"raw": "7m8KM0HcWGOPw28Gt",
+				"startIndex": 29,
+				"endIndex": 46,
+				"normalized": "7m8KM0HcWGOPw28Gt",
+				"value": "7",
+				"unit": "m8KM0HcWGOPw28Gt"
+			},
+			{
+				"type": "(-token",
+				"raw": "(",
+				"startIndex": 46,
+				"endIndex": 47,
+				"normalized": "(",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "r19",
+				"startIndex": 47,
+				"endIndex": 50,
+				"normalized": "r19",
+				"value": "r19"
+			}
+		]
+	},
+	"tests/fuzz/2abe9406-c063-4e9a-85ac-b13660671553": {
+		"css": "ak]P0A}808G\"lQh{R5M!QyOWE}oC2{2K TIa9}zb2oXWREY]0aj5J\\\r\nBJ5CO-16W5H7noF 19䀹41H3e8Z9%tg[O5AHEY24xh'9\"\"c34Q\"iiC0e45Da5f\"F5X3\"o(",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "ak",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "ak",
+				"value": "ak"
+			},
+			{
+				"type": "]-token",
+				"raw": "]",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "]",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "P0A",
+				"startIndex": 3,
+				"endIndex": 6,
+				"normalized": "P0A",
+				"value": "P0A"
+			},
+			{
+				"type": "}-token",
+				"raw": "}",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "}",
+				"value": null
+			},
+			{
+				"type": "dimension-token",
+				"raw": "808G",
+				"startIndex": 7,
+				"endIndex": 11,
+				"normalized": "808G",
+				"value": "808",
+				"unit": "G"
+			},
+			{
+				"type": "string-token",
+				"raw": "\"lQh{R5M!QyOWE}oC2{2K TIa9}zb2oXWREY]0aj5J\\\r\nBJ5CO-16W5H7noF 19䀹41H3e8Z9%tg[O5AHEY24xh'9\"",
+				"startIndex": 11,
+				"endIndex": 102,
+				"normalized": "\"lQh{R5M!QyOWE}oC2{2K TIa9}zb2oXWREY]0aj5J\\\nBJ5CO-16W5H7noF 19䀹41H3e8Z9%tg[O5AHEY24xh'9\"",
+				"value": "lQh{R5M!QyOWE}oC2{2K TIa9}zb2oXWREY]0aj5J\\\nBJ5CO-16W5H7noF 19䀹41H3e8Z9%tg[O5AHEY24xh'9"
+			},
+			{
+				"type": "string-token",
+				"raw": "\"c34Q\"",
+				"startIndex": 102,
+				"endIndex": 108,
+				"normalized": "\"c34Q\"",
+				"value": "c34Q"
+			},
+			{
+				"type": "ident-token",
+				"raw": "iiC0e45Da5f",
+				"startIndex": 108,
+				"endIndex": 119,
+				"normalized": "iiC0e45Da5f",
+				"value": "iiC0e45Da5f"
+			},
+			{
+				"type": "string-token",
+				"raw": "\"F5X3\"",
+				"startIndex": 119,
+				"endIndex": 125,
+				"normalized": "\"F5X3\"",
+				"value": "F5X3"
+			},
+			{
+				"type": "function-token",
+				"raw": "o(",
+				"startIndex": 125,
+				"endIndex": 127,
+				"normalized": "o(",
+				"value": "o"
+			}
+		]
+	},
+	"tests/fuzz/4e630a47-507b-4b79-b00f-57f7dc1cc79d": {
+		"css": "\u000e7rSD6I5L1lglVRlL2X7BbEk\\3HCd\r94 \\\u0000skoW25d4%l64UUskN\"pHun\"!",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "\u000e",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "\u000e",
+				"value": "\u000e"
+			},
+			{
+				"type": "dimension-token",
+				"raw": "7rSD6I5L1lglVRlL2X7BbEk\\3HCd",
+				"startIndex": 1,
+				"endIndex": 29,
+				"normalized": "7rSD6I5L1lglVRlL2X7BbEk\u0003HCd",
+				"value": "7",
+				"unit": "rSD6I5L1lglVRlL2X7BbEk\u0003HCd"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\r",
+				"startIndex": 29,
+				"endIndex": 30,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "number-token",
+				"raw": "94",
+				"startIndex": 30,
+				"endIndex": 32,
+				"normalized": "94",
+				"value": "94"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": " ",
+				"startIndex": 32,
+				"endIndex": 33,
+				"normalized": " ",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "\\\u0000skoW25d4",
+				"startIndex": 33,
+				"endIndex": 43,
+				"normalized": "�skoW25d4",
+				"value": "�skoW25d4"
+			},
+			{
+				"type": "delim-token",
+				"raw": "%",
+				"startIndex": 43,
+				"endIndex": 44,
+				"normalized": "%",
+				"value": "%"
+			},
+			{
+				"type": "ident-token",
+				"raw": "l64UUskN",
+				"startIndex": 44,
+				"endIndex": 52,
+				"normalized": "l64UUskN",
+				"value": "l64UUskN"
+			},
+			{
+				"type": "string-token",
+				"raw": "\"pHun\"",
+				"startIndex": 52,
+				"endIndex": 58,
+				"normalized": "\"pHun\"",
+				"value": "pHun"
+			},
+			{
+				"type": "delim-token",
+				"raw": "!",
+				"startIndex": 58,
+				"endIndex": 59,
+				"normalized": "!",
+				"value": "!"
+			}
+		]
+	},
+	"tests/fuzz/4f865903-e4dd-4a0b-83ed-e630cfa9dcca": {
+		"css": "gzO0{(p{DzQ7\u0000(a1;r1iN7w)",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "gzO0",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "gzO0",
+				"value": "gzO0"
+			},
+			{
+				"type": "{-token",
+				"raw": "{",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "{",
+				"value": null
+			},
+			{
+				"type": "(-token",
+				"raw": "(",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "(",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "p",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "p",
+				"value": "p"
+			},
+			{
+				"type": "{-token",
+				"raw": "{",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "{",
+				"value": null
+			},
+			{
+				"type": "function-token",
+				"raw": "DzQ7\u0000(",
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+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "u",
+				"value": "u"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "k2a76",
+				"startIndex": 3,
+				"endIndex": 8,
+				"normalized": "k2a76",
+				"value": "k2a76"
+			},
+			{
+				"type": "}-token",
+				"raw": "}",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "}",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "y4\\6fb9ONI\\",
+				"startIndex": 9,
+				"endIndex": 20,
+				"normalized": "y4澹ONI�",
+				"value": "y4澹ONI�"
+			}
+		]
+	},
+	"tests/hash/0001": {
+		"css": "#1\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#1",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "#1",
+				"value": "1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0002": {
+		"css": "#-2\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#-2",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "#-2",
+				"value": "-2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0003": {
+		"css": "#--3\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#--3",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "#--3",
+				"value": "--3"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0004": {
+		"css": "#---4\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#---4",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "#---4",
+				"value": "---4"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0005": {
+		"css": "#a\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#a",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "#a",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0006": {
+		"css": "#-b\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#-b",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "#-b",
+				"value": "-b"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0007": {
+		"css": "#--c\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#--c",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "#--c",
+				"value": "--c"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0008": {
+		"css": "#---d\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#---d",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "#---d",
+				"value": "---d"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0009": {
+		"css": "#_\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#_",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "#_",
+				"value": "_"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0010": {
+		"css": "#_1\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#_1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "#_1",
+				"value": "_1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0011": {
+		"css": "#-\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#-",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "#-",
+				"value": "-"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0012": {
+		"css": "#+\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "#",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "#",
+				"value": "#"
+			},
+			{
+				"type": "delim-token",
+				"raw": "+",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "+",
+				"value": "+"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0013": {
+		"css": "##\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "#",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "#",
+				"value": "#"
+			},
+			{
+				"type": "delim-token",
+				"raw": "#",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "#",
+				"value": "#"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hash/0014": {
+		"css": "#",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "#",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "#",
+				"value": "#"
+			}
+		]
+	},
+	"tests/hash/0015": {
+		"css": "#aa𐀀\n",
+		"tokens": [
+			{
+				"type": "hash-token",
+				"raw": "#aa𐀀",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "#aa𐀀",
+				"value": "aa𐀀"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0001": {
+		"css": "-\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "-",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "-",
+				"value": "-"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0002": {
+		"css": "-1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-1",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "-1",
+				"value": "-1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0003": {
+		"css": "-.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-.1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-.1",
+				"value": "-.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0004": {
+		"css": "--1\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "--1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "--1",
+				"value": "--1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0005": {
+		"css": "-0\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-0",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "-0",
+				"value": "-0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/hyphen-minus/0006": {
+		"css": "-->\n",
+		"tokens": [
+			{
+				"type": "CDC-token",
+				"raw": "-->",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-->",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0001": {
+		"css": "foo\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "foo",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "foo",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0002": {
+		"css": "--\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "--",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "--",
+				"value": "--"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0003": {
+		"css": "--0\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "--0",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "--0",
+				"value": "--0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0004": {
+		"css": "-\\\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "-",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "-",
+				"value": "-"
+			},
+			{
+				"type": "delim-token",
+				"raw": "\\",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\\",
+				"value": "\\"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0005": {
+		"css": "-\\ \n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "-\\ ",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "- ",
+				"value": "- "
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0006": {
+		"css": "--💅\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "--💅",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "--💅",
+				"value": "--💅"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0007": {
+		"css": "-§\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "-§",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-§",
+				"value": "-§"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0008": {
+		"css": "-×\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "-×",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-×",
+				"value": "-×"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident/0009": {
+		"css": "--a𐀀\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "--a𐀀",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "--a𐀀",
+				"value": "--a𐀀"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0001": {
+		"css": "url(foo)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(foo)",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "url(foo)",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0002": {
+		"css": "\\75 Rl(foo)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "\\75 Rl(foo)",
+				"startIndex": 0,
+				"endIndex": 11,
+				"normalized": "uRl(foo)",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0003": {
+		"css": "uR\\6c (foo)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "uR\\6c (foo)",
+				"startIndex": 0,
+				"endIndex": 11,
+				"normalized": "uRl(foo)",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0004": {
+		"css": "url('foo')\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "url(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "url(",
+				"value": "url"
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 4,
+				"endIndex": 9,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 10,
+				"endIndex": 11,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0005": {
+		"css": "url( 'foo')\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "url(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "url(",
+				"value": "url"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": " ",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": " ",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 5,
+				"endIndex": 10,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 10,
+				"endIndex": 11,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0006": {
+		"css": "url(  'foo')\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "url(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "url(",
+				"value": "url"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "  ",
+				"startIndex": 4,
+				"endIndex": 6,
+				"normalized": "  ",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 6,
+				"endIndex": 11,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 12,
+				"endIndex": 13,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0007": {
+		"css": "url(   'foo')\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "url(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "url(",
+				"value": "url"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "   ",
+				"startIndex": 4,
+				"endIndex": 7,
+				"normalized": "   ",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 7,
+				"endIndex": 12,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 12,
+				"endIndex": 13,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 13,
+				"endIndex": 14,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0008": {
+		"css": "not-url(   'foo')\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "not-url(",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "not-url(",
+				"value": "not-url"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "   ",
+				"startIndex": 8,
+				"endIndex": 11,
+				"normalized": "   ",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 11,
+				"endIndex": 16,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 16,
+				"endIndex": 17,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 17,
+				"endIndex": 18,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/ident-like/0009": {
+		"css": "url(   foo)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(   foo)",
+				"startIndex": 0,
+				"endIndex": 11,
+				"normalized": "url(   foo)",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/left-curly-bracket/0001": {
+		"css": "{\n",
+		"tokens": [
+			{
+				"type": "{-token",
+				"raw": "{",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "{",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/left-parenthesis/0001": {
+		"css": "(\n",
+		"tokens": [
+			{
+				"type": "(-token",
+				"raw": "(",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "(",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/left-square-bracket/0001": {
+		"css": "[\n",
+		"tokens": [
+			{
+				"type": "[-token",
+				"raw": "[",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "[",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/less-than/0001": {
+		"css": "<\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "<",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "<",
+				"value": "<"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/less-than/0002": {
+		"css": "<!--\n",
+		"tokens": [
+			{
+				"type": "CDO-token",
+				"raw": "<!--",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "<!--",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/less-than/0003": {
+		"css": "<--\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "<",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "<",
+				"value": "<"
+			},
+			{
+				"type": "ident-token",
+				"raw": "--",
+				"startIndex": 1,
+				"endIndex": 3,
+				"normalized": "--",
+				"value": "--"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/less-than/0004": {
+		"css": "<!-\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "<",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "<",
+				"value": "<"
+			},
+			{
+				"type": "delim-token",
+				"raw": "!",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "!",
+				"value": "!"
+			},
+			{
+				"type": "delim-token",
+				"raw": "-",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "-",
+				"value": "-"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0001": {
+		"css": "10\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "10",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "10",
+				"value": "10"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0002": {
+		"css": "+10\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+10",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "+10",
+				"value": "+10"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0003": {
+		"css": "-10\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-10",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-10",
+				"value": "-10"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0004": {
+		"css": "0\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "0",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "0",
+				"value": "0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0005": {
+		"css": "+0\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+0",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "+0",
+				"value": "+0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0006": {
+		"css": "-0\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-0",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "-0",
+				"value": "-0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0007": {
+		"css": ".0\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": ".0",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": ".0",
+				"value": ".0"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0008": {
+		"css": ".1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": ".1",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": ".1",
+				"value": ".1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0009": {
+		"css": "+.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+.1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "+.1",
+				"value": "+.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0010": {
+		"css": "-.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-.1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "-.1",
+				"value": "-.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0011": {
+		"css": "1.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "1.1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "1.1",
+				"value": "1.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0012": {
+		"css": "+1.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+1.1",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "+1.1",
+				"value": "+1.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0013": {
+		"css": "-1.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-1.1",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "-1.1",
+				"value": "-1.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0014": {
+		"css": "1.1e2\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "1.1e2",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "1.1e2",
+				"value": "1.1e2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0015": {
+		"css": "+1.1e+2\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+1.1e+2",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "+1.1e+2",
+				"value": "+1.1e+2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0016": {
+		"css": "-1.1e-2\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-1.1e-2",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "-1.1e-2",
+				"value": "-1.1e-2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0017": {
+		"css": "-1.1e-22\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-1.1e-22",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "-1.1e-22",
+				"value": "-1.1e-22"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0018": {
+		"css": "-1.1e-22e\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "-1.1e-22e",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "-1.1e-22e",
+				"value": "-1.1e-22",
+				"unit": "e"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0019": {
+		"css": "1e+\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "1e",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "1e",
+				"value": "1",
+				"unit": "e"
+			},
+			{
+				"type": "delim-token",
+				"raw": "+",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "+",
+				"value": "+"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/number/0020": {
+		"css": ".2.7\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": ".2",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": ".2",
+				"value": ".2"
+			},
+			{
+				"type": "number-token",
+				"raw": ".7",
+				"startIndex": 2,
+				"endIndex": 4,
+				"normalized": ".7",
+				"value": ".7"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/numeric/0001": {
+		"css": "-123.753e-2\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "-123.753e-2",
+				"startIndex": 0,
+				"endIndex": 11,
+				"normalized": "-123.753e-2",
+				"value": "-123.753e-2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/numeric/0002": {
+		"css": "-123.753e-2px\n",
+		"tokens": [
+			{
+				"type": "dimension-token",
+				"raw": "-123.753e-2px",
+				"startIndex": 0,
+				"endIndex": 13,
+				"normalized": "-123.753e-2px",
+				"value": "-123.753e-2",
+				"unit": "px"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 13,
+				"endIndex": 14,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/numeric/0003": {
+		"css": "-123.753e-2%\n",
+		"tokens": [
+			{
+				"type": "percentage-token",
+				"raw": "-123.753e-2%",
+				"startIndex": 0,
+				"endIndex": 12,
+				"normalized": "-123.753e-2%",
+				"value": "-123.753e-2"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 12,
+				"endIndex": 13,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/numeric/0004": {
+		"css": "1.2.3\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "1.2",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "1.2",
+				"value": "1.2"
+			},
+			{
+				"type": "number-token",
+				"raw": ".3",
+				"startIndex": 3,
+				"endIndex": 5,
+				"normalized": ".3",
+				"value": ".3"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/plus/0001": {
+		"css": "+\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "+",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "+",
+				"value": "+"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/plus/0002": {
+		"css": "+1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+1",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "+1",
+				"value": "+1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/plus/0003": {
+		"css": "+.1\n",
+		"tokens": [
+			{
+				"type": "number-token",
+				"raw": "+.1",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "+.1",
+				"value": "+.1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/plus/0004": {
+		"css": "++1\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "+",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "+",
+				"value": "+"
+			},
+			{
+				"type": "number-token",
+				"raw": "+1",
+				"startIndex": 1,
+				"endIndex": 3,
+				"normalized": "+1",
+				"value": "+1"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/reverse-solidus/0001": {
+		"css": "\\\n",
+		"tokens": [
+			{
+				"type": "delim-token",
+				"raw": "\\",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "\\",
+				"value": "\\"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/reverse-solidus/0002": {
+		"css": "\\#\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\#",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "#",
+				"value": "#"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/reverse-solidus/0003": {
+		"css": "\\ \n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\ ",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": " ",
+				"value": " "
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 2,
+				"endIndex": 3,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/reverse-solidus/0004": {
+		"css": "\\61 b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\61 b",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "ab",
+				"value": "ab"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/reverse-solidus/0005": {
+		"css": "\\",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "�",
+				"value": "�"
+			}
+		]
+	},
+	"tests/right-curly-bracket/0001": {
+		"css": "}\n",
+		"tokens": [
+			{
+				"type": "}-token",
+				"raw": "}",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "}",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/right-parenthesis/0001": {
+		"css": ")\n",
+		"tokens": [
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/right-square-bracket/0001": {
+		"css": "]\n",
+		"tokens": [
+			{
+				"type": "]-token",
+				"raw": "]",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "]",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/semi-colon/0001": {
+		"css": ";\n",
+		"tokens": [
+			{
+				"type": "semicolon-token",
+				"raw": ";",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": ";",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 1,
+				"endIndex": 2,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/string/0001": {
+		"css": "\"foo\"\n'foo'\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"foo\"",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "\"foo\"",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'foo'",
+				"startIndex": 6,
+				"endIndex": 11,
+				"normalized": "'foo'",
+				"value": "foo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 11,
+				"endIndex": 12,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/string/0002": {
+		"css": "\"foo",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"foo",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "\"foo",
+				"value": "foo"
+			}
+		]
+	},
+	"tests/string/0003": {
+		"css": "\"fo\no\"",
+		"tokens": [
+			{
+				"type": "bad-string-token",
+				"raw": "\"fo",
+				"startIndex": 0,
+				"endIndex": 3,
+				"normalized": "\"fo",
+				"value": "fo"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "o",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "o",
+				"value": "o"
+			},
+			{
+				"type": "string-token",
+				"raw": "\"",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\"",
+				"value": ""
+			}
+		]
+	},
+	"tests/string/0004": {
+		"css": "\"fo\\\no\"\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"fo\\\no\"",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "\"fo\\\no\"",
+				"value": "fo\\\no"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/string/0005": {
+		"css": "\"fo\\",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"fo\\",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "\"fo�",
+				"value": "fo�"
+			}
+		]
+	},
+	"tests/string/0006": {
+		"css": "\"esc\\61 ped\"\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"esc\\61 ped\"",
+				"startIndex": 0,
+				"endIndex": 12,
+				"normalized": "\"escaped\"",
+				"value": "escaped"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 12,
+				"endIndex": 13,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/string/0007": {
+		"css": "\"foo\\\"",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"foo\\\"",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "\"foo\"",
+				"value": "foo\""
+			}
+		]
+	},
+	"tests/string/0008": {
+		"css": "\"'foo'\"\n'\"foo\"'\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"'foo'\"",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "\"'foo'\"",
+				"value": "'foo'"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'\"foo\"'",
+				"startIndex": 8,
+				"endIndex": 15,
+				"normalized": "'\"foo\"'",
+				"value": "\"foo\""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 15,
+				"endIndex": 16,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/string/0009": {
+		"css": "\"\\\"foo\\\"\"\n'\\'foo\\''\n",
+		"tokens": [
+			{
+				"type": "string-token",
+				"raw": "\"\\\"foo\\\"\"",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "\"\"foo\"\"",
+				"value": "\"foo\""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			},
+			{
+				"type": "string-token",
+				"raw": "'\\'foo\\''",
+				"startIndex": 10,
+				"endIndex": 19,
+				"normalized": "''foo''",
+				"value": "'foo'"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 19,
+				"endIndex": 20,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0001": {
+		"css": "url(\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(\n",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "url(\n",
+				"value": ""
+			}
+		]
+	},
+	"tests/url/0002": {
+		"css": "url(a\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(a\n",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "url(a\n",
+				"value": "a"
+			}
+		]
+	},
+	"tests/url/0003": {
+		"css": "url( a\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( a\n",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "url( a\n",
+				"value": "a"
+			}
+		]
+	},
+	"tests/url/0004": {
+		"css": "url()\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url()",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "url()",
+				"value": ""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0005": {
+		"css": "url( )\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( )",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "url( )",
+				"value": ""
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0006": {
+		"css": "url( a)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( a)",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "url( a)",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0007": {
+		"css": "url( a )\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( a )",
+				"startIndex": 0,
+				"endIndex": 8,
+				"normalized": "url( a )",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 8,
+				"endIndex": 9,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0008": {
+		"css": "url( \\) )\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url( \\) )",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "url( ) )",
+				"value": ")"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0009": {
+		"css": "url(https://https:⁄⁄www.netmeister.org@https://www.netmeister.org/https:⁄⁄www.netmeister.org⁄?https://www.netmeister.org=https://www.netmeister.org;https://www.netmeister.org#https://www.netmeister.org)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(https://https:⁄⁄www.netmeister.org@https://www.netmeister.org/https:⁄⁄www.netmeister.org⁄?https://www.netmeister.org=https://www.netmeister.org;https://www.netmeister.org#https://www.netmeister.org)",
+				"startIndex": 0,
+				"endIndex": 212,
+				"normalized": "url(https://https:⁄⁄www.netmeister.org@https://www.netmeister.org/https:⁄⁄www.netmeister.org⁄?https://www.netmeister.org=https://www.netmeister.org;https://www.netmeister.org#https://www.netmeister.org)",
+				"value": "https://https:⁄⁄www.netmeister.org@https://www.netmeister.org/https:⁄⁄www.netmeister.org⁄?https://www.netmeister.org=https://www.netmeister.org;https://www.netmeister.org#https://www.netmeister.org"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 212,
+				"endIndex": 213,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0010": {
+		"css": "url(https://www.netmeister.org/%62%6C%6F%67/%75%72%6C%73%2E%68%74%6D%6C?!@#$%25=+_\\)\\(*&^#top)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "url(https://www.netmeister.org/%62%6C%6F%67/%75%72%6C%73%2E%68%74%6D%6C?!@#$%25=+_\\)\\(*&^#top)",
+				"startIndex": 0,
+				"endIndex": 94,
+				"normalized": "url(https://www.netmeister.org/%62%6C%6F%67/%75%72%6C%73%2E%68%74%6D%6C?!@#$%25=+_)(*&^#top)",
+				"value": "https://www.netmeister.org/%62%6C%6F%67/%75%72%6C%73%2E%68%74%6D%6C?!@#$%25=+_)(*&^#top"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 94,
+				"endIndex": 95,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0011": {
+		"css": "Url(a)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "Url(a)",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "Url(a)",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0012": {
+		"css": "uRl(a)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "uRl(a)",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "uRl(a)",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0013": {
+		"css": "urL(a)\n",
+		"tokens": [
+			{
+				"type": "url-token",
+				"raw": "urL(a)",
+				"startIndex": 0,
+				"endIndex": 6,
+				"normalized": "urL(a)",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0014": {
+		"css": "uri(a)\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "uri(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "uri(",
+				"value": "uri"
+			},
+			{
+				"type": "ident-token",
+				"raw": "a",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/url/0015": {
+		"css": "uul(a)\n",
+		"tokens": [
+			{
+				"type": "function-token",
+				"raw": "uul(",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "uul(",
+				"value": "uul"
+			},
+			{
+				"type": "ident-token",
+				"raw": "a",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": ")-token",
+				"raw": ")",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": ")",
+				"value": null
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0001": {
+		"css": "\n",
+		"tokens": [
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0002": {
+		"css": " \n",
+		"tokens": [
+			{
+				"type": "whitespace-token",
+				"raw": " \n",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": " \n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0003": {
+		"css": "a  b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "a",
+				"startIndex": 0,
+				"endIndex": 1,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "  ",
+				"startIndex": 1,
+				"endIndex": 3,
+				"normalized": "  ",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "b",
+				"startIndex": 3,
+				"endIndex": 4,
+				"normalized": "b",
+				"value": "b"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0004": {
+		"css": "\\61 b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\61 b",
+				"startIndex": 0,
+				"endIndex": 5,
+				"normalized": "ab",
+				"value": "ab"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0005": {
+		"css": "\\000061 b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\000061 b",
+				"startIndex": 0,
+				"endIndex": 9,
+				"normalized": "ab",
+				"value": "ab"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 9,
+				"endIndex": 10,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0006": {
+		"css": "\\61  b\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "\\61 ",
+				"startIndex": 0,
+				"endIndex": 4,
+				"normalized": "a",
+				"value": "a"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": " ",
+				"startIndex": 4,
+				"endIndex": 5,
+				"normalized": " ",
+				"value": null
+			},
+			{
+				"type": "ident-token",
+				"raw": "b",
+				"startIndex": 5,
+				"endIndex": 6,
+				"normalized": "b",
+				"value": "b"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 6,
+				"endIndex": 7,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0007": {
+		"css": "\t\n",
+		"tokens": [
+			{
+				"type": "whitespace-token",
+				"raw": "\t\n",
+				"startIndex": 0,
+				"endIndex": 2,
+				"normalized": "\t\n",
+				"value": null
+			}
+		]
+	},
+	"tests/whitespace/0008": {
+		"css": "f\\ o\\\to\n",
+		"tokens": [
+			{
+				"type": "ident-token",
+				"raw": "f\\ o\\\to",
+				"startIndex": 0,
+				"endIndex": 7,
+				"normalized": "f o\to",
+				"value": "f o\to"
+			},
+			{
+				"type": "whitespace-token",
+				"raw": "\n",
+				"startIndex": 7,
+				"endIndex": 8,
+				"normalized": "\n",
+				"value": null
+			}
+		]
+	}
+}
diff --git a/components/DataLiberation/URL/class-csstokenizer.php b/components/DataLiberation/URL/class-csstokenizer.php
new file mode 100644
index 00000000..2864b2bc
--- /dev/null
+++ b/components/DataLiberation/URL/class-csstokenizer.php
@@ -0,0 +1,1595 @@
+<?php
+
+namespace WordPress\DataLiberation\URL;
+
+use function WordPress\Encoding\_wp_scan_utf8;
+use function WordPress\Encoding\_wp_scrub_utf8_fallback;
+use function WordPress\Encoding\utf8_codepoint_at;
+use function WordPress\Encoding\codepoint_to_utf8_bytes;
+
+/**
+ * Tokenizes CSS according to the CSS Syntax Level 3 specification.
+ *
+ * This class implements the CSS tokenization algorithm as defined in:
+ * https://www.w3.org/TR/css-syntax-3/
+ *
+ * ## Design choices:
+ *
+ * ### On-the-fly normalization
+ *
+ * The CSS Spec requires the following normalization step:
+ *
+ * > Replace any U+000D CARRIAGE RETURN (CR) code points, U+000C FORM FEED (FF)
+ * > code points, or pairs of U+000D CARRIAGE RETURN (CR) followed by U+000A LINE
+ * > FEED (LF) in input by a single U+000A LINE FEED (LF) code point.
+ * > Replace any U+0000 NULL or surrogate code points in input with U+FFFD REPLACEMENT
+ * > CHARACTER (�).
+ *
+ * This tokenizer delays normalization as much as possible, rather than preprocessing
+ * the entire input upfront. This avoids the upfront allocation cost for clean CSS
+ * and preserves original byte positions for accurate raw token extraction. A part
+ * of the normalization is performed on-the-fly as the tokens are consumed. The rest
+ * of it is done once the token value is requested.
+ *
+ * ### No EOF token
+ *
+ * The EOF token is a CSS parsing concept, not CSS tokenization concept. Therefore,
+ * this tokenizer does not produce it.
+ *
+ * ## Usage
+ *
+ * The next_token() method is the main entry point for tokenizing a CSS string.
+ * It will consume the next token from the input stream and return true if a token
+ * was found. Otherwise, it will return false:
+ *
+ * ```php
+ * $css = 'width: 10px;';
+ * $processor = CSSTokenizer::create( $css );
+ * while ( $processor->next_token() ) {
+ *     echo $processor->get_normalized_token();
+ * }
+ * // Outputs:
+ * // width: 10px;
+ * ```
+ *
+ * @TODO: More usage examples.
+ * @see https://www.w3.org/TR/css-syntax-3/#tokenization
+ */
+class CSSTokenizer {
+	/**
+	 * Token type constants matching the CSS Syntax Level 3 specification.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#tokenization
+	 */
+	public const TOKEN_WHITESPACE = 'whitespace-token';
+	public const TOKEN_COMMENT    = 'comment';
+	public const TOKEN_STRING     = 'string-token';
+
+	/**
+	 * BAD-STRING tokens occur when a string contains an unescaped newline.
+	 *
+	 * Valid strings: "hello", 'world', "line1\Aline2" (escaped newline)
+	 * Invalid (produces bad-string): "hello
+	 *                                 world"  (literal newline breaks the string)
+	 *
+	 * The tokenizer stops at the newline and produces a bad-string token for error recovery.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-bad-string-token
+	 */
+	public const TOKEN_BAD_STRING    = 'bad-string-token';
+	public const TOKEN_HASH          = 'hash-token';
+	public const TOKEN_DELIM         = 'delim-token';
+	public const TOKEN_NUMBER        = 'number-token';
+	public const TOKEN_PERCENTAGE    = 'percentage-token';
+	public const TOKEN_DIMENSION     = 'dimension-token';
+	public const TOKEN_AT_KEYWORD    = 'at-keyword-token';
+	public const TOKEN_COLON         = 'colon-token';
+	public const TOKEN_SEMICOLON     = 'semicolon-token';
+	public const TOKEN_COMMA         = 'comma-token';
+	public const TOKEN_LEFT_PAREN    = '(-token';
+	public const TOKEN_RIGHT_PAREN   = ')-token';
+	public const TOKEN_LEFT_BRACKET  = '[-token';
+	public const TOKEN_RIGHT_BRACKET = ']-token';
+	public const TOKEN_LEFT_BRACE    = '{-token';
+	public const TOKEN_RIGHT_BRACE   = '}-token';
+	public const TOKEN_FUNCTION      = 'function-token';
+
+	/**
+	 * URL tokens represent unquoted URLs in url() notation.
+	 *
+	 * Valid: url(image.jpg), url(https://example.com)
+	 * Quoted URLs are parsed as url( + string-token + ), not url-token.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-url-token
+	 */
+	public const TOKEN_URL = 'url-token';
+
+	/**
+	 * BAD-URL tokens occur when a URL contains invalid characters.
+	 *
+	 * Invalid characters: quotes ("), apostrophes ('), parentheses (()
+	 * Example invalid: url(image(.jpg) or url(image".jpg)
+	 *
+	 * When detected, the tokenizer consumes everything up to ) or EOF.
+	 * This prevents the bad URL from breaking subsequent tokens.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-bad-url-token
+	 */
+	public const TOKEN_BAD_URL = 'bad-url-token';
+
+	/**
+	 * Identifier tokens, such as `color`, `margin-top`, `red`,
+	 * `inherit`, `--my-var`, `\escaped`, `über` (Unicode), etc.
+	 *
+	 * They can contain: letters, digits, hyphens, underscores, non-ASCII, escapes
+	 * and cannot start with a digit (unless preceded by a hyphen).
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-ident-token
+	 */
+	public const TOKEN_IDENT = 'ident-token';
+
+	/**
+	 * CDC (Comment Delimiter Close) token: -->
+	 *
+	 * Legacy token from when CSS was embedded in HTML <style> tags
+	 * and needed to be hidden from old browsers using HTML comments:
+	 *
+	 *   <style>
+	 *   <!--
+	 *   body { color: red; }
+	 *   -->
+	 *   </style>
+	 *
+	 * Modern CSS no longer needs these, but they're preserved for compatibility.
+	 * In stylesheets, they're typically treated like whitespace.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-CDC-token
+	 */
+	public const TOKEN_CDC = 'CDC-token';
+
+	/**
+	 * CDO (Comment Delimiter Open) token: <!--
+	 *
+	 * Legacy token from when CSS was embedded in HTML <style> tags.
+	 * See TOKEN_CDC for full explanation of HTML comment compatibility.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#typedef-CDO-token
+	 */
+	public const TOKEN_CDO = 'CDO-token';
+
+	/**
+	 * @var string
+	 */
+	private $css;
+
+	/**
+	 * @var int
+	 */
+	private $length = 0;
+
+	/**
+	 * @var int
+	 */
+	private $at = 0;
+
+	/**
+	 * The type of the current token. One of the self::TOKEN_* constants.
+	 *
+	 * @var string|null
+	 */
+	private $token_type = null;
+
+	/**
+	 * The byte offset at which the current token starts.
+	 *
+	 * Example:
+	 *
+	 * background-image: url(https://example.com/image.jpg);
+	 *                   ^ token_starts_at
+	 *
+	 * @var int|null
+	 */
+	private $token_starts_at = null;
+
+	/**
+	 * The byte length of the current token.
+	 *
+	 * Example:
+	 *
+	 * background-image: url(https://example.com/image.jpg);
+	 *                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+	 *                             token_length
+	 *
+	 * @var int|null
+	 */
+	private $token_length = null;
+
+	/**
+	 * The byte offset at which the value of the current token starts.
+	 *
+	 * It is used for STRING and URL tokens. For example:
+	 *
+	 * background-image: url(https://example.com/image.jpg);
+	 *                       ^ token_value_starts_at
+	 *
+	 * @var int|null
+	 */
+	private $token_value_starts_at = null;
+
+	/**
+	 * The byte offset at which the value of the current token starts.
+	 *
+	 * It is relevant for STRING and URL tokens. For example:
+	 *
+	 * background-image: url(https://example.com/image.jpg);
+	 *                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+	 *                             token_value_length
+	 *
+	 * @var int|null
+	 */
+	private $token_value_length = null;
+
+	/**
+	 * The string value of the current token.
+	 *
+	 * For numbers, this is a float.
+	 * For identifiers/functions/strings/URLs with escapes, this is a decoded string.
+	 * Otherwise, it's null and the value is computed from token indices.
+	 *
+	 * @var string|float|null
+	 */
+	private $token_value = null;
+
+	/**
+	 * The unit of the current token, e.g. "px", "em", "deg", etc.
+	 *
+	 * @var string|null
+	 */
+	private $token_unit = null;
+
+	/**
+	 * Constructor for the CSS tokenizer.
+	 *
+	 * Do not instantiate directly. Use CSSTokenizer::create() instead.
+	 *
+	 * @param string $css         CSS source to tokenize.
+	 */
+	private function __construct( string $css ) {
+		$this->css    = $css;
+		$this->length = strlen( $css );
+	}
+
+	/**
+	 * Creates a CSS tokenizer for the given CSS string.
+	 *
+	 * Use this method to create a CSS tokenizer instance.
+	 *
+	 * ## Current Support
+	 *
+	 * - The only supported document encoding is `UTF-8`, which is the default value.
+	 *
+	 * @param string $css      CSS source to tokenize.
+	 * @param string $encoding Text encoding of the document; must be default of 'UTF-8'.
+	 * @return static|null The created tokenizer if successful, otherwise null.
+	 */
+	public static function create( string $css, string $encoding = 'UTF-8' ) {
+		if ( 'UTF-8' !== $encoding ) {
+			return null;
+		}
+
+		return new static( $css );
+	}
+
+	/**
+	 * Moves to the next token in the CSS stream.
+	 *
+	 * Implements the main tokenization loop, consuming the next token from the input stream.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-token
+	 *
+	 * @return bool Whether a token was found.
+	 */
+	public function next_token(): bool {
+		$this->after_token();
+
+		// Bale out once we reach the end.
+		if ( $this->at >= $this->length ) {
+			return false;
+		}
+
+		/*
+		 * CSS comments. They are not preserved as tokens in the specification, but we
+		 * still track them.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#consume-comment
+		 */
+		if (
+			$this->at + 1 < $this->length &&
+			'/' === $this->css[ $this->at ] &&
+			'*' === $this->css[ $this->at + 1 ]
+		) {
+			$this->token_type            = self::TOKEN_COMMENT;
+			$this->token_starts_at       = $this->at;
+			$this->token_value_starts_at = $this->at;
+
+			$end                      = strpos( $this->css, '*/', $this->at + 2 );
+			$this->at                 = false !== $end ? $end + 2 : $this->length;
+			$this->token_length       = $this->at - $this->token_starts_at;
+			$this->token_value_length = $this->token_length - 4;
+			return true;
+		}
+
+		/*
+		 * Whitespace tokens.
+		 *
+		 * We consider U+000A LINE FEED, U+0009 CHARACTER TABULATION, and U+0020 SPACE bytes covered by the spec.
+		 * In addition, we also capture U+000D CARRIAGE RETURN and U+000C FORM FEED that are normally converted to
+		 * U+000A LINE FEED during the preprocessing phase.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#newline
+		 * @see https://www.w3.org/TR/css-syntax-3/#whitespace
+		 */
+		$whitespace_length = strspn( $this->css, "\t\n\f\r ", $this->at );
+		if ( $whitespace_length > 0 ) {
+			$this->token_type      = self::TOKEN_WHITESPACE;
+			$this->token_length    = $whitespace_length;
+			$this->token_starts_at = $this->at;
+			$this->at             += $whitespace_length;
+			return true;
+		}
+
+		/*
+		 * String tokens with either " or ' as delimiters.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#consume-string-token
+		 */
+		if ( '"' === $this->css[ $this->at ] || "'" === $this->css[ $this->at ] ) {
+			return $this->consume_string();
+		}
+
+		$char                  = $this->css[ $this->at ];
+		$this->token_starts_at = $this->at;
+
+		/*
+		 * U+0023 NUMBER SIGN (#)
+		 *
+		 * A hash token is created when # is followed by an ident code point or valid escape.
+		 * This is commonly used for hex colors (#fff) or ID selectors (#header).
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#consume-token
+		 */
+		if ( '#' === $char ) {
+			if ( $this->at + 1 < $this->length ) {
+				if (
+					$this->consume_ident_codepoint( $this->at + 1 ) > 0 ||
+					// The next two input code points are a valid escape.
+					$this->is_valid_escape( $this->at + 1 )
+				) {
+					// Create a <hash-token>.
+					++$this->at;
+
+					// We skip this check as we don't track the type flag:
+					// > If the next 3 input code points would start an ident sequence,
+					// > set the <hash-token>'s type flag to "id".
+
+					// Consume an ident sequence, and set the <hash-token>'s value to the returned string.
+					$this->consume_ident_sequence();
+					$this->token_type   = self::TOKEN_HASH;
+					$this->token_length = $this->at - $this->token_starts_at;
+					return true;
+				}
+			}
+			// Otherwise, return a <delim-token> with its value set to the current input code point.
+			++$this->at;
+			$this->token_type   = self::TOKEN_DELIM;
+			$this->token_length = 1;
+			return true;
+		}
+
+		/*
+		 * Simple single-byte tokens
+		 *
+		 * These characters form their own tokens when encountered.
+		 * Note: ( tokens here are not function tokens - those are handled
+		 * in consume_ident_like() when ( follows an identifier.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#tokenization
+		 */
+		$simple = array(
+			'(' => self::TOKEN_LEFT_PAREN,
+			')' => self::TOKEN_RIGHT_PAREN,
+			',' => self::TOKEN_COMMA,
+			':' => self::TOKEN_COLON,
+			';' => self::TOKEN_SEMICOLON,
+			'[' => self::TOKEN_LEFT_BRACKET,
+			']' => self::TOKEN_RIGHT_BRACKET,
+			'{' => self::TOKEN_LEFT_BRACE,
+			'}' => self::TOKEN_RIGHT_BRACE,
+		);
+		if ( isset( $simple[ $char ] ) ) {
+			++$this->at;
+			$this->token_type   = $simple[ $char ];
+			$this->token_length = 1;
+			return true;
+		}
+
+		/*
+		 * U+0040 COMMERCIAL AT (@)
+		 *
+		 * An at-keyword is @ followed by an identifier, used for at-rules like
+		 * @media, @import, @keyframes, etc.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#consume-token
+		 */
+		if ( '@' === $char ) {
+			++$this->at;
+			// If the next 3 input code points after the @ would start an ident sequence,
+			// consume an ident sequence, create an <at-keyword-token> with its value set to the returned value,
+			// and return it.
+			if ( $this->check_if_3_code_points_start_an_ident_sequence( $this->at ) ) {
+				$this->consume_ident_sequence();
+				$this->token_type   = self::TOKEN_AT_KEYWORD;
+				$this->token_length = $this->at - $this->token_starts_at;
+				return true;
+			} else {
+				// Otherwise, return a <delim-token> with its value set to the current input code point.
+				$this->token_type   = self::TOKEN_DELIM;
+				$this->token_length = 1;
+				return true;
+			}
+		}
+
+		/*
+		 * Numbers start with digits, the plus sign, minus sign, and decimal point.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#starts-with-a-number
+		 */
+		if ( $this->would_next_3_code_points_start_a_number() ) {
+			return $this->consume_numeric();
+		}
+
+		/*
+		 * U+002D HYPHEN-MINUS (-)
+		 */
+		if ( '-' === $char ) {
+			// This case is covered above:
+			// > If the input stream starts with a number.
+
+			/*
+			 * If followed by another hyphen and >, this is a CDC token (-->)
+			 *
+			 * Comment Delimiter Close - legacy HTML comment syntax in CSS.
+			 *
+			 * @see https://www.w3.org/TR/css-syntax-3/#CDC-token-diagram
+			 */
+			if (
+				$this->at + 2 < $this->length &&
+				'-' === $this->css[ $this->at + 1 ] &&
+				'>' === $this->css[ $this->at + 2 ]
+			) {
+				// Consume them and return a <CDC-token>.
+				$this->at          += 3;
+				$this->token_type   = self::TOKEN_CDC;
+				$this->token_length = 3;
+				return true;
+			}
+
+			// Otherwise, if the input stream starts with an ident sequence,
+			// reconsume the current input code point, consume an ident-like
+			// token, and return it.
+			if ( $this->check_if_3_code_points_start_an_ident_sequence( $this->at ) ) {
+				return $this->consume_ident_like();
+			}
+
+			// Otherwise, return a <delim-token> with its value set to the current input code point.
+			++$this->at;
+			$this->token_type   = self::TOKEN_DELIM;
+			$this->token_length = 1;
+			return true;
+		}
+
+		/*
+		 * U+003C LESS-THAN SIGN (<)
+		 * If followed by !--, this is a CDO token (<!--)
+		 *
+		 * Comment Delimiter Open - legacy HTML comment syntax in CSS.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#CDO-token-diagram
+		 */
+		if ( '<' === $char && $this->at + 3 < $this->length &&
+			'!' === $this->css[ $this->at + 1 ] &&
+			'-' === $this->css[ $this->at + 2 ] &&
+			'-' === $this->css[ $this->at + 3 ] ) {
+			// Consume them and return a <CDO-token>.
+			$this->at          += 4;
+			$this->token_type   = self::TOKEN_CDO;
+			$this->token_length = 4;
+			return true;
+		}
+
+		/*
+		 * Ident-start code point
+		 *
+		 * If the input stream starts with an ident sequence, reconsume the current
+		 * input code point, consume an ident-like token, and return it.
+		 *
+		 * Could be an identifier, function, or url() token.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#consume-ident-like-token
+		 */
+		if ( $this->check_if_3_code_points_start_an_ident_sequence( $this->at ) ) {
+			return $this->consume_ident_like();
+		}
+
+		/*
+		 * Delim token (delimiter)
+		 *
+		 * Any code point that doesn't match above rules becomes a delim token.
+		 * Handle multi-byte UTF-8 characters properly.
+		 *
+		 * @see https://www.w3.org/TR/css-syntax-3/#delim-token-diagram
+		 */
+		if ( ord( $char ) >= 0x80 ) {
+			$new_at         = $this->at;
+			$invalid_length = 0;
+			if ( 1 !== _wp_scan_utf8( $this->css, $new_at, $invalid_length, null, 1 ) ) {
+				/**
+				 * Trouble ahead!
+				 * Bytes at $at are not a valid UTF-8 sequence.
+				 *
+				 * We'll move forward by $invalid_length bytes and continue processing.
+				 * Later on, during the string decoding, we'll replace the invalid bytes with U+FFFD
+				 * via maximal subpart”replacement.
+				 */
+				$matched_bytes = $invalid_length;
+			} else {
+				$matched_bytes = $new_at - $this->at;
+			}
+
+			$this->at          += $matched_bytes;
+			$this->token_type   = self::TOKEN_DELIM;
+			$this->token_length = $matched_bytes;
+			return true;
+		}
+
+		// Single ASCII delim.
+		++$this->at;
+		$this->token_type   = self::TOKEN_DELIM;
+		$this->token_length = 1;
+		return true;
+	}
+
+	/**
+	 * Gets the current token type.
+	 *
+	 * @return string|null
+	 */
+	public function get_token_type(): ?string {
+		return $this->token_type;
+	}
+
+	/**
+	 * Gets the normalized token text from the CSS source.
+	 *
+	 * Returns the token with CSS normalization and escape decoding applied:
+	 * - CSS escapes decoded (e.g., \6c → l, \2f → /, \A → newline)
+	 * - \r\n, \r, \f → \n
+	 * - \x00 → U+FFFD (�)
+	 *
+	 * This is different from get_token_value() which returns the semantic value
+	 * (e.g., for strings: content without quotes; for numbers: numeric value).
+	 *
+	 * @return string|null
+	 */
+	public function get_normalized_token(): ?string {
+		if ( null === $this->token_starts_at || null === $this->token_length ) {
+			return null;
+		}
+
+		return $this->decode_string_or_url(
+			$this->token_starts_at,
+			$this->token_length
+		);
+	}
+
+	/**
+	 * Gets the raw, unnormalized token text from the CSS source.
+	 *
+	 * Returns the exact bytes from the source without any normalization.
+	 * This preserves original line endings (\r\n, \r, \f) and null bytes.
+	 *
+	 * @return string|null
+	 */
+	public function get_unnormalized_token(): ?string {
+		if ( null === $this->token_starts_at || null === $this->token_length ) {
+			return null;
+		}
+		return substr( $this->css, $this->token_starts_at, $this->token_length );
+	}
+
+	/**
+	 * Gets the current token value as a normalized and decoded string. This is
+	 * a slight divergence from the CSS Syntax Level 3 spec, where all the numberic
+	 * values are parsed as numbers. This tokenizer is only concerned with their
+	 * textual representation.
+	 *
+	 * Returns the semantic value of the token per CSS Syntax Level 3 spec:
+	 *
+	 * - For delimiters: the single code point
+	 * - For numbers/percentages: the string representation of the number
+	 * - For dimensions: the string representation of the number (use get_token_unit() for the unit)
+	 * - For identifiers/functions/hash/at-keywords: the decoded identifier string
+	 * - For strings/URLs: the decoded string value
+	 * - For other tokens: null
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#token-value
+	 * @return string|null
+	 */
+	public function get_token_value() {
+		if ( null === $this->token_value ) {
+			if ( null === $this->token_starts_at || null === $this->token_length ) {
+				return null;
+			}
+
+			switch ( $this->token_type ) {
+				case self::TOKEN_HASH:
+					// Hash value starts after the # character.
+					$this->token_value = $this->decode_string_or_url( $this->token_starts_at + 1, $this->token_length - 1 );
+					break;
+
+				case self::TOKEN_AT_KEYWORD:
+					// At-keyword value starts after the @ character.
+					$this->token_value = $this->decode_string_or_url( $this->token_starts_at + 1, $this->token_length - 1 );
+					break;
+
+				case self::TOKEN_FUNCTION:
+					// Function name is everything except the final (.
+					$this->token_value = $this->decode_string_or_url( $this->token_starts_at, $this->token_length - 1 );
+					break;
+
+				case self::TOKEN_IDENT:
+					// Identifier is the entire token.
+					$this->token_value = $this->decode_string_or_url( $this->token_starts_at, $this->token_length );
+					break;
+
+				case self::TOKEN_STRING:
+				case self::TOKEN_BAD_STRING:
+				case self::TOKEN_URL:
+					// Decode and cache the string/URL value.
+					if ( null !== $this->token_value_starts_at && null !== $this->token_value_length ) {
+						$this->token_value = $this->decode_string_or_url(
+							$this->token_value_starts_at,
+							$this->token_value_length
+						);
+						$this->token_value = $this->token_value;
+					} else {
+						$this->token_value = null;
+					}
+					break;
+
+				case self::TOKEN_DELIM:
+					// Delim value is the single code point.
+					$this->token_value = $this->decode_string_or_url( $this->token_starts_at, $this->token_length );
+					break;
+
+				case self::TOKEN_NUMBER:
+					// Return the string representation of the number (not parsed to float).
+					$this->token_value = substr( $this->css, $this->token_starts_at, $this->token_length );
+					break;
+
+				case self::TOKEN_PERCENTAGE:
+					// Return the string representation of the number (without the %).
+					$this->token_value = substr( $this->css, $this->token_starts_at, $this->token_length - 1 );
+					break;
+
+				case self::TOKEN_DIMENSION:
+					// Return the string representation of the number (without the unit).
+					$this->token_value = substr( $this->get_normalized_token(), 0, -strlen( $this->token_unit ) );
+					break;
+
+				default:
+					$this->token_value = null;
+					break;
+			}
+		}
+
+		return $this->token_value;
+	}
+
+	/**
+	 * Gets the token start at.
+	 *
+	 * @return int|null
+	 */
+	public function get_token_start(): ?int {
+		return $this->token_starts_at;
+	}
+
+	/**
+	 * Gets the token length.
+	 *
+	 * @return int|null
+	 */
+	public function get_token_length(): ?int {
+		return $this->token_length;
+	}
+
+	/**
+	 * Gets the unit for dimension tokens.
+	 *
+	 * @return string|null
+	 */
+	public function get_token_unit(): ?string {
+		return $this->token_unit;
+	}
+
+	/**
+	 * Gets the byte at where the token value starts (for STRING and URL tokens).
+	 *
+	 * @return int|null
+	 */
+	public function get_token_value_start(): ?int {
+		return $this->token_value_starts_at;
+	}
+
+	/**
+	 * Gets the byte length of the token value (for STRING and URL tokens).
+	 *
+	 * @return int|null
+	 */
+	public function get_token_value_length(): ?int {
+		return $this->token_value_length;
+	}
+
+	/**
+	 * Clears token state between tokens.
+	 */
+	private function after_token(): void {
+		$this->token_type            = null;
+		$this->token_starts_at       = null;
+		$this->token_length          = null;
+		$this->token_value           = null;
+		$this->token_unit            = null;
+		$this->token_value_starts_at = null;
+		$this->token_value_length    = null;
+	}
+
+	/**
+	 * Consumes a string token.
+	 *
+	 * Strings are quoted with either " or ' and can contain escape sequences.
+	 * Newlines inside strings (without escaping) make the string invalid.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-string-token
+	 *
+	 * @return bool
+	 */
+	private function consume_string(): bool {
+		// Initially create a <string-token> with its value set to the empty string.
+		$this->token_starts_at = $this->at;
+		$ending_char           = $this->css[ $this->at ];
+
+		// Skip past the opening quote.
+		++$this->at;
+		$value_starts_at = $this->at;
+
+		// Characters that need special handling: the ending quote, newlines, backslashes.
+		$special_chars = "'" === $ending_char ? "'\n\f\r\\" : "\"\n\f\r\\";
+
+		while ( $this->at < $this->length ) {
+			// Consume normal characters until we hit a special character.
+			$normal_len = strcspn( $this->css, $special_chars, $this->at );
+			if ( $normal_len > 0 ) {
+				$this->at += $normal_len;
+			}
+
+			if ( $this->at >= $this->length ) {
+				break; // EOF.
+			}
+
+			$char = $this->css[ $this->at ];
+			switch ( $char ) {
+				case $ending_char:
+					// Ending quote.
+					// Return the <string-token>.
+					++$this->at;
+					$this->token_type            = self::TOKEN_STRING;
+					$this->token_length          = $this->at - $this->token_starts_at;
+					$this->token_value_starts_at = $value_starts_at;
+					$this->token_value_length    = $this->at - $value_starts_at - 1;
+					return true;
+
+				case "\n":
+				case "\f":
+				case "\r":
+					/*
+					 * Newline.
+					 *
+					 * This is a parse error. Reconsume the current input code point,
+					 * create a <bad-string-token>, and return it.
+					 *
+					 * Unescaped newlines are not allowed in strings. To include a newline,
+					 * it must be escaped as \A or the string must end and a new one begin.
+					 *
+					 * @see https://www.w3.org/TR/css-syntax-3/#consume-string-token
+					 */
+					$this->token_type            = self::TOKEN_BAD_STRING;
+					$this->token_length          = $this->at - $this->token_starts_at;
+					$this->token_value_starts_at = $value_starts_at;
+					$this->token_value_length    = $this->at - $value_starts_at;
+					return true;
+
+				case '\\':
+					// U+005C REVERSE SOLIDUS (\)
+					// If the next input code point is EOF, do nothing.
+					++$this->at;
+					if ( $this->at >= $this->length ) {
+						// Backslash-EOF: do nothing, just consume the backslash.
+						continue 2;
+					}
+
+					// Otherwise, if the next input code point is a newline, consume it.
+					$next = $this->css[ $this->at ];
+					if ( "\n" === $next || "\f" === $next ) {
+						++$this->at;
+						continue 2;
+					} elseif ( "\r" === $next ) {
+						++$this->at;
+						// Handle \r\n as a single newline.
+						if ( $this->at < $this->length && "\n" === $this->css[ $this->at ] ) {
+							++$this->at;
+						}
+						continue 2;
+					}
+
+					// Otherwise, (the stream starts with a valid escape) consume an escaped
+					// code point (just to advance position, don't store the result).
+					$this->decode_escape_at( $this->at, $matched_bytes );
+					$this->at += $matched_bytes;
+					continue 2;
+
+				default:
+					_doing_it_wrong( __METHOD__, 'Unexpected character in string: ' . $char, '1.0.0' );
+					break;
+			}
+		}
+
+		// EOF
+		// This is a parse error. Return the <string-token>.
+		$this->token_type            = self::TOKEN_STRING;
+		$this->token_length          = $this->at - $this->token_starts_at;
+		$this->token_value_starts_at = $value_starts_at;
+		$this->token_value_length    = $this->at - $value_starts_at;
+		return true;
+	}
+
+	/**
+	 * Consumes a numeric token (number, percentage, dimension).
+	 *
+	 * Numbers can be integers or decimals, with optional sign and exponent.
+	 * They can be followed by % (percentage) or an identifier (dimension).
+	 *
+	 * @TODO: Keep track of the "type" flag ("integer" or "number").
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-numeric-token
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-number
+	 *
+	 * @return bool
+	 */
+	private function consume_numeric(): bool {
+		// Consume a number and let number be the result.
+
+		// If the next input code point is U+002B PLUS SIGN (+) or U+002D HYPHEN-MINUS (-),
+		// consume it and append it to repr.
+		if ( '+' === $this->css[ $this->at ] || '-' === $this->css[ $this->at ] ) {
+			++$this->at;
+		}
+
+		// While the next input code point is a digit, consume it and append it to repr.
+		$digits = strspn( $this->css, '0123456789', $this->at );
+		if ( $digits > 0 ) {
+			$this->at += $digits;
+		}
+
+		// If the next 2 input code points are U+002E FULL STOP (.) followed by a digit, then.
+		if (
+			$this->at + 1 < $this->length &&
+			'.' === $this->css[ $this->at ] &&
+			$this->css[ $this->at + 1 ] >= '0' &&
+			$this->css[ $this->at + 1 ] <= '9'
+		) {
+			// Consume them.
+			++$this->at;
+			// While the next input code point is a digit, consume it and append it to repr.
+			$digits = strspn( $this->css, '0123456789', $this->at );
+			if ( $digits > 0 ) {
+				$this->at += $digits;
+			}
+		}
+
+		// If the next 2 or 3 input code points are U+0045 LATIN CAPITAL LETTER E (E)
+		// or U+0065 LATIN SMALL LETTER E (e), optionally followed by U+002D HYPHEN-MINUS (-)
+		// or U+002B PLUS SIGN (+), followed by a digit, then.
+		if ( $this->at < $this->length ) {
+			$e = $this->css[ $this->at ];
+			if ( 'e' === $e || 'E' === $e ) {
+				$save_pos = $this->at;
+				++$this->at;
+				$has_exp = false;
+
+				if ( $this->at < $this->length ) {
+					$next = $this->css[ $this->at ];
+					if ( ( '+' === $next || '-' === $next ) && $this->at + 1 < $this->length &&
+						$this->css[ $this->at + 1 ] >= '0' && $this->css[ $this->at + 1 ] <= '9' ) {
+						// Consume them.
+						++$this->at;
+						$has_exp = true;
+					} elseif ( $next >= '0' && $next <= '9' ) {
+						$has_exp = true;
+					}
+				}
+
+				if ( $has_exp ) {
+					// While the next input code point is a digit, consume it and append it to repr.
+					$digits = strspn( $this->css, '0123456789', $this->at );
+					if ( $digits > 0 ) {
+						$this->at += $digits;
+					}
+				} else {
+					$this->at = $save_pos;
+				}
+			}
+		}
+
+		/**
+		 * This is the end of spec section 4.3.12. Consume a number.
+		 * We still have some work to do as specified in section 4.3.3. Consume a numeric token:
+		 * https://www.w3.org/TR/css-syntax-3/#consume-numeric-token
+		 */
+
+		// If the next 3 input code points would start an ident sequence, then.
+		if ( $this->check_if_3_code_points_start_an_ident_sequence( $this->at ) ) {
+			// Create a <dimension-token> with the same value and type flag as number,
+			// and a unit set initially to the empty string.
+			// Consume an ident sequence. Set the <dimension-token>'s unit to the returned value.
+			$unit_starts_at = $this->at;
+			$this->consume_ident_sequence();
+			$this->token_unit   = $this->decode_string_or_url( $unit_starts_at, $this->at - $unit_starts_at );
+			$this->token_type   = self::TOKEN_DIMENSION;
+			$this->token_length = $this->at - $this->token_starts_at;
+			return true;
+		}
+
+		// Otherwise, if the next input code point is U+0025 PERCENTAGE SIGN (%), consume it.
+		// Create a <percentage-token> with the same value as number, and return it.
+		if ( $this->at < $this->length && '%' === $this->css[ $this->at ] ) {
+			++$this->at;
+			$this->token_type   = self::TOKEN_PERCENTAGE;
+			$this->token_length = $this->at - $this->token_starts_at;
+			return true;
+		}
+
+		// Otherwise, create a <number-token> with the same value and type flag as number, and return it.
+		$this->token_type   = self::TOKEN_NUMBER;
+		$this->token_length = $this->at - $this->token_starts_at;
+		return true;
+	}
+
+	/**
+	 * Consumes an ident-like token (function, url, ident).
+	 *
+	 * After consuming an identifier, checks if it's followed by '(' to determine
+	 * if it's a function or url() token, otherwise it's a plain identifier.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-ident-like-token
+	 *
+	 * @return bool
+	 */
+	private function consume_ident_like(): bool {
+		// Consume an ident sequence, and let string be the result.
+		$ident_start = $this->at;
+		$decoded     = $this->consume_ident_sequence();
+		$string      = $decoded ?? $this->decode_string_or_url( $ident_start, $this->at - $ident_start );
+
+		// If string's value is an ASCII case-insensitive match for "url",
+		// and the next input code point is U+0028 LEFT PARENTHESIS (().
+		if ( 0 === strcasecmp( $string, 'url' ) && $this->at < $this->length && '(' === $this->css[ $this->at ] ) {
+			// Consume it.
+			++$this->at;
+
+			// While the next two input code points are whitespace, consume the next input code point.
+			$ws_len = strspn( $this->css, "\t\n\f\r ", $this->at );
+
+			// If the next one or two input code points are U+0022 QUOTATION MARK ("),
+			// U+0027 APOSTROPHE ('), or whitespace followed by U+0022 QUOTATION MARK (")
+			// or U+0027 APOSTROPHE (').
+			if ( $this->at + $ws_len < $this->length ) {
+				$next = $this->css[ $this->at + $ws_len ];
+				if ( '"' === $next || "'" === $next ) {
+					// then create a <function-token> with its value set to string and return it.
+					if ( null !== $decoded ) {
+						$this->token_value = $decoded;
+					}
+					$this->token_type   = self::TOKEN_FUNCTION;
+					$this->token_length = $this->at - $this->token_starts_at;
+					return true;
+				}
+			}
+
+			// Otherwise, consume a url token, and return it.
+			$this->at += $ws_len;
+			return $this->consume_url();
+		}
+
+		// Otherwise, if the next input code point is U+0028 LEFT PARENTHESIS (().
+		if ( $this->at < $this->length && '(' === $this->css[ $this->at ] ) {
+			// Consume it.
+			++$this->at;
+			// Create a <function-token> with its value set to string and return it.
+			if ( null !== $decoded ) {
+				$this->token_value = $decoded;
+			}
+			$this->token_type   = self::TOKEN_FUNCTION;
+			$this->token_length = $this->at - $this->token_starts_at;
+			return true;
+		}
+
+		// Otherwise, create an <ident-token> with its value set to string and return it.
+		if ( null !== $decoded ) {
+			$this->token_value = $decoded;
+		}
+		$this->token_type   = self::TOKEN_IDENT;
+		$this->token_length = $this->at - $this->token_starts_at;
+		return true;
+	}
+
+	/**
+	 * Consumes a url token.
+	 *
+	 * URL tokens can contain unquoted URLs with escape sequences but not quotes,
+	 * parentheses, or certain control characters. Invalid characters create a
+	 * bad-url token.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-url-token
+	 *
+	 * @return bool
+	 */
+	private function consume_url(): bool {
+		// Initially create a <url-token> with its value set to the empty string.
+		// Consume as much whitespace as possible.
+		$this->at += strspn( $this->css, "\t\n\f\r ", $this->at );
+
+		$value_starts_at = $this->at;
+
+		// Repeatedly consume the next input code point from the stream.
+		while ( $this->at < $this->length ) {
+			// U+0029 RIGHT PARENTHESIS ())
+			// Return the <url-token>.
+			if ( ')' === $this->css[ $this->at ] ) {
+				++$this->at;
+				$this->token_type            = self::TOKEN_URL;
+				$this->token_length          = $this->at - $this->token_starts_at;
+				$this->token_value_starts_at = $value_starts_at;
+				$this->token_value_length    = $this->at - $value_starts_at - 1;
+				return true;
+			}
+
+			// whitespace
+			// Consume as much whitespace as possible. If the next input code point is
+			// U+0029 RIGHT PARENTHESIS ()) or EOF, consume it and return the <url-token>
+			// (if EOF was encountered, this is a parse error); otherwise, consume the
+			// remnants of a bad url, create a <bad-url-token>, and return it.
+			$ws_len = strspn( $this->css, "\t\n\f\r ", $this->at );
+			if ( $ws_len > 0 ) {
+				$value_ends_at = $this->at;
+				$this->at     += $ws_len;
+				// Accept either ) or EOF after whitespace.
+				if ( $this->at >= $this->length ) {
+					// EOF is a parse error, but we return the <url-token> anyway.
+					$this->token_type            = self::TOKEN_URL;
+					$this->token_length          = $this->at - $this->token_starts_at;
+					$this->token_value_starts_at = $value_starts_at;
+					$this->token_value_length    = $value_ends_at - $value_starts_at;
+					return true;
+				}
+
+				if ( ')' === $this->css[ $this->at ] ) {
+					// Skip the closing parenthesis and return the <url-token>.
+					++$this->at;
+					$this->token_type            = self::TOKEN_URL;
+					$this->token_length          = $this->at - $this->token_starts_at;
+					$this->token_value_starts_at = $value_starts_at;
+					$this->token_value_length    = $value_ends_at - $value_starts_at;
+					return true;
+				}
+
+				return $this->consume_remnants_of_bad_url();
+			}
+
+			// These codepoints trigger a parse error.
+			$byte = ord( $this->css[ $this->at ] );
+			if (
+				'"' === $this->css[ $this->at ] ||
+				"'" === $this->css[ $this->at ] ||
+				'(' === $this->css[ $this->at ] ||
+
+				// Non-printable code point.
+				$byte <= 0x08 ||
+
+				// Line Tabulation.
+				0x0B === $byte ||
+
+				// Control characters.
+				( $byte >= 0x000E && $byte <= 0x001F ) ||
+
+				// Delete.
+				0x7F === $byte
+			) {
+				// Consume the remnants of a bad url,
+				// create a <bad-url-token>, and return it.
+				return $this->consume_remnants_of_bad_url();
+			}
+
+			// U+005C REVERSE SOLIDUS (\)
+			// If the stream starts with a valid escape, consume an escaped code point.
+			if ( '\\' === $this->css[ $this->at ] ) {
+				if ( $this->is_valid_escape( $this->at ) ) {
+					++$this->at;
+					$this->decode_escape_at( $this->at, $matched_bytes );
+					$this->at += $matched_bytes;
+					continue;
+				}
+				// Otherwise, this is a parse error. Consume the remnants of a bad url,
+				// create a <bad-url-token>, and return it.
+				return $this->consume_remnants_of_bad_url();
+			}
+
+			$at             = $this->at;
+			$invalid_length = 0;
+			if ( 1 !== _wp_scan_utf8( $this->css, $at, $invalid_length, null, 1 ) ) {
+				/**
+				 * Trouble ahead!
+				 * Bytes at $at are not a valid UTF-8 sequence.
+				 *
+				 * We'll move forward by $invalid_length bytes and continue processing.
+				 * Later on, during the string decoding, we'll replace the invalid bytes with U+FFFD
+				 * via maximal subpart”replacement.
+				 */
+				$this->at += $invalid_length;
+			} else {
+				$this->at = $at;
+			}
+		}
+
+		// EOF
+		// This is a parse error. Return the <url-token>.
+		$this->token_type            = self::TOKEN_URL;
+		$this->token_length          = $this->at - $this->token_starts_at;
+		$this->token_value_starts_at = $value_starts_at;
+		$this->token_value_length    = $this->at - $value_starts_at;
+		return true;
+	}
+
+	/**
+	 * Finishes a bad url token by consuming remnants.
+	 *
+	 * When an invalid character is encountered in a URL, we must consume
+	 * the remainder of the URL up to the closing ) or EOF.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-remnants-of-bad-url
+	 *
+	 * @return bool
+	 */
+	private function consume_remnants_of_bad_url(): bool {
+		while ( $this->at < $this->length ) {
+			$this->at += strcspn( $this->css, ')\\', $this->at );
+
+			if ( $this->at >= $this->length ) {
+				break;
+			}
+
+			if ( '\\' === $this->css[ $this->at ] ) {
+				++$this->at;
+				if ( $this->is_valid_escape( $this->at - 1 ) ) {
+					$this->decode_escape_at( $this->at, $matched_bytes );
+					$this->at += $matched_bytes;
+					continue;
+				}
+			} elseif ( ')' === $this->css[ $this->at ] ) {
+				++$this->at;
+				break;
+			}
+		}
+
+		$this->token_type   = self::TOKEN_BAD_URL;
+		$this->token_length = $this->at - $this->token_starts_at;
+		return true;
+	}
+
+	/**
+	 * Consumes an identifier sequence.
+	 *
+	 * Identifiers can contain letters, digits, hyphens, underscores, non-ASCII
+	 * characters, and escape sequences. Null bytes are replaced with U+FFFD.
+	 *
+	 * Returns the decoded identifier string if escapes were encountered,
+	 * or null if no decoding was needed (can use raw substring).
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-name
+	 */
+	private function consume_ident_sequence() {
+		while ( $this->at < $this->length ) {
+			$codepoint_bytes = $this->consume_ident_codepoint( $this->at );
+			if ( $codepoint_bytes > 0 ) {
+				$this->at += $codepoint_bytes;
+				continue;
+			}
+
+			if ( $this->is_valid_escape( $this->at ) ) {
+				++$this->at;
+
+				$this->decode_escape_at( $this->at, $matched_bytes );
+				$this->at += $matched_bytes;
+				continue;
+			}
+
+			break;
+		}
+	}
+
+	/**
+	 * Ident-start code point
+	 *     A letter, a non-ASCII code point, or U+005F LOW LINE (_).
+	 *
+	 * Ident code point
+	 *     An ident-start code point, a digit, or U+002D HYPHEN-MINUS (-).
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#ident-start-code-point
+	 * @return int The number of bytes consumed.
+	 */
+	private function consume_ident_codepoint( $at ): int {
+		// ident code points.
+		if ( ( $this->css[ $at ] >= '0' && $this->css[ $at ] <= '9' ) ||
+			'-' === $this->css[ $at ] ) {
+			return 1;
+		}
+
+		return $this->consume_ident_start_codepoint( $at );
+	}
+
+
+	/**
+	 * Ident-start code point
+	 *     A letter, a non-ASCII code point, or U+005F LOW LINE (_).
+	 *
+	 * Ident code point
+	 *     An ident-start code point, a digit, or U+002D HYPHEN-MINUS (-).
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#ident-start-code-point
+	 * @return int The number of bytes consumed.
+	 */
+	private function consume_ident_start_codepoint( $at ): int {
+		if ( $at > $this->length ) {
+			return 0;
+		}
+
+		// ASCII codepoints.
+		if ( ( $this->css[ $at ] >= 'A' && $this->css[ $at ] <= 'Z' ) ||
+			( $this->css[ $at ] >= 'a' && $this->css[ $at ] <= 'z' ) ||
+			'_' === $this->css[ $at ] ) {
+			return 1;
+		}
+
+		// Special case for null bytes – they are replaced with U+FFFD during preprocessing.
+		if ( "\x00" === $this->css[ $at ] ) {
+			return 1;
+		}
+
+		$new_at         = $at;
+		$invalid_length = 0;
+		if ( 1 !== _wp_scan_utf8( $this->css, $new_at, $invalid_length, null, 1 ) ) {
+			/**
+			 * Trouble ahead!
+			 * Bytes at $at are not a valid UTF-8 sequence.
+			 *
+			 * We'll move forward by $invalid_length bytes and continue processing.
+			 * Later on, during the string decoding, we'll replace the invalid bytes with U+FFFD
+			 * via maximal subpart”replacement.
+			 */
+			return $invalid_length;
+		}
+
+		$codepoint_byte_length = $new_at - $at;
+		$codepoint             = utf8_codepoint_at( $this->css, $at );
+		if ( null !== $codepoint && $codepoint >= 0x80 ) {
+			return $codepoint_byte_length;
+		}
+		return 0;
+	}
+
+	/**
+	 * Decodes a string or URL value with escape sequences and normalization.
+	 *
+	 * Fast path: If the slice contains no special characters, returns the raw
+	 * substring with almost zero allocations.
+	 *
+	 * Slow path: Builds the decoded string by optionally processing escapes and
+	 * normalizing line endings and null bytes.
+	 *
+	 * @param int $start           Start byte offset.
+	 * @param int $length          Length of the substring to decode.
+	 * @return string Decoded/normalized string.
+	 */
+	private function decode_string_or_url( int $start, int $length ): string {
+		// Fast path: check if any processing is needed.
+		$slice         = _wp_scrub_utf8_fallback( substr( $this->css, $start, $length ) );
+		$special_chars = "\\\r\f\x00";
+		if ( false === strpbrk( $slice, $special_chars ) ) {
+			// No special chars - return raw substring (almost zero allocations).
+			return $slice;
+		}
+
+		// Slow path: build decoded string (one allocation).
+		$decoded = '';
+		$at      = $start;
+		$end     = $start + $length;
+
+		while ( $at < $end ) {
+			// Find next special character.
+			$normal_len = strcspn( $this->css, $special_chars, $at );
+			if ( $normal_len > 0 ) {
+				// Clamp to not exceed the end boundary.
+				$normal_len = min( $normal_len, $end - $at );
+				$decoded   .= substr( $this->css, $at, $normal_len );
+				$at        += $normal_len;
+			}
+
+			if ( $at >= $end ) {
+				break;
+			}
+
+			$char = $this->css[ $at ];
+
+			// Handle escapes (if enabled).
+			if ( '\\' === $char ) {
+				if ( $this->is_valid_escape( $at ) ) {
+					++$at;
+					$decoded .= $this->decode_escape_at( $at, $bytes_consumed );
+					$at      += $bytes_consumed;
+					continue;
+				}
+				// Invalid escape - consume the backslash and keep going.
+				$decoded .= '\\';
+				++$at;
+				continue;
+			}
+
+			// CSS normalization: \r\n, \r, and \f all become \n.
+			if ( "\r" === $char ) {
+				$decoded .= "\n";
+				++$at;
+				// Handle \r\n as single newline.
+				if ( $at < $end && "\n" === $this->css[ $at ] ) {
+					++$at;
+				}
+				continue;
+			}
+
+			if ( "\f" === $char ) {
+				$decoded .= "\n";
+				++$at;
+				continue;
+			}
+
+			// Null bytes become U+FFFD.
+			if ( "\x00" === $char ) {
+				$decoded .= "\u{FFFD}";
+				++$at;
+				continue;
+			}
+		}
+
+		return $decoded;
+	}
+
+	/**
+	 * Decodes an escape sequence starting at the given offset without
+	 * modifying $this->at.
+	 *
+	 * Escape sequences are backslash followed by 1-6 hex digits (with optional
+	 * trailing whitespace) or any other character. Invalid code points are
+	 * replaced with U+FFFD.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#consume-escaped-code-point
+	 *
+	 * @param int $offset Byte offset (should point to the character after the backslash).
+	 * @param int &$bytes_consumed Output parameter: number of bytes consumed.
+	 * @return string The decoded character(s).
+	 */
+	private function decode_escape_at( int $offset, &$bytes_consumed ): string {
+		// This method assumes the U+005C REVERSE SOLIDUS (\) has already been consumed
+		// and the next input code point has already been verified to be part of a valid
+		// escape sequence.
+		$at = $offset;
+
+		// EOF.
+		if ( $at >= $this->length ) {
+			// This is a parse error. Return U+FFFD REPLACEMENT CHARACTER (�).
+			$bytes_consumed = 0;
+			return "\u{FFFD}";
+		}
+
+		// Hex digits.
+		$hex_len = strspn( $this->css, '0123456789ABCDEFabcdef', $at );
+		if ( $hex_len > 0 ) {
+			// Consume up to 6 hex digits.
+			$hex_len = min( $hex_len, 6 );
+			$hex     = substr( $this->css, $at, $hex_len );
+			$at     += $hex_len;
+
+			// If the next input code point is whitespace, consume it as well.
+			if ( $at < $this->length ) {
+				$next = $this->css[ $at ];
+				if ( "\t" === $next || "\n" === $next || "\f" === $next || ' ' === $next ) {
+					++$at;
+				} elseif ( "\r" === $next ) {
+					++$at;
+					// Handle \r\n as a single whitespace – the preprocessing phase would replace \r\n with \n.
+					if ( $at < $this->length && "\n" === $this->css[ $at ] ) {
+						++$at;
+					}
+				}
+			}
+
+			$bytes_consumed = $at - $offset;
+			// Convert the hex digits to a UTF-8 string.
+			return codepoint_to_utf8_bytes( hexdec( $hex ) );
+		}
+
+		// Anything else.
+		// Return the current input code point.
+		// Null bytes are replaced with U+FFFD during preprocessing.
+		if ( "\x00" === $this->css[ $at ] ) {
+			$bytes_consumed = 1;
+			return "\u{FFFD}";
+		}
+
+		$new_at         = $at;
+		$invalid_length = 0;
+		if ( 1 !== _wp_scan_utf8( $this->css, $new_at, $invalid_length, null, 1 ) ) {
+			/**
+			 * Trouble ahead!
+			 * Bytes at $at are not a valid UTF-8 sequence.
+			 *
+			 * We'll move forward by $invalid_length bytes and continue processing.
+			 * Later on, during the string decoding, we'll replace the invalid bytes with U+FFFD
+			 * via maximal subpart”replacement.
+			 */
+			$matched_bytes = $invalid_length;
+		} else {
+			$matched_bytes = $new_at - $at;
+		}
+
+		$bytes_consumed = $matched_bytes;
+		return substr( $this->css, $at, $matched_bytes );
+	}
+
+	/**
+	 * Checks if current position starts a valid escape sequence.
+	 *
+	 * A valid escape is a backslash not followed by a newline or EOF.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#starts-with-a-valid-escape
+	 *
+	 * @param int $offset Byte offset.
+	 * @return bool
+	 */
+	private function is_valid_escape( int $offset ): bool {
+		// If the first code point is not U+005C REVERSE SOLIDUS (\), return false.
+		if ( $offset >= $this->length || '\\' !== $this->css[ $offset ] ) {
+			return false;
+		}
+		// Otherwise, if the second code point is a newline, return false.
+		if ( $offset + 1 >= $this->length ) {
+			// Second code point is EOF - this is a valid escape per spec (weird!)
+			// Are we sure we're interpreting the spec correctly?
+			return true;
+		}
+
+		// Otherwise, if the second code point is not a newline, return true.
+		return (
+			"\n" !== $this->css[ $offset + 1 ] &&
+
+			// Form feed is normalized to newline during preprocessing.
+			"\f" !== $this->css[ $offset + 1 ] &&
+
+			// Carriage return is normalized to newline during preprocessing.
+			"\r" !== $this->css[ $offset + 1 ]
+
+			// We don't need to check for \r\n separately here. The \r check alone covers
+			// that scenario.
+		);
+	}
+
+	/**
+	 * Checks if the next 3 code points would start a number.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#starts-with-a-number
+	 *
+	 * @return bool
+	 */
+	private function would_next_3_code_points_start_a_number(): bool {
+		if ( $this->at >= $this->length ) {
+			return false;
+		}
+
+		// Look at the first code point.
+
+		// U+002B PLUS SIGN (+) or U+002D HYPHEN-MINUS (-).
+		if ( '+' === $this->css[ $this->at ] || '-' === $this->css[ $this->at ] ) {
+			if ( $this->at + 1 >= $this->length ) {
+				return false;
+			}
+			// If the second code point is a digit, return true.
+			if ( $this->css[ $this->at + 1 ] >= '0' && $this->css[ $this->at + 1 ] <= '9' ) {
+				return true;
+			}
+			// Otherwise, the second code point must be a full stop (.) and the third code point must be a digit.
+			if ( '.' === $this->css[ $this->at + 1 ] && $this->at + 2 < $this->length ) {
+				return $this->css[ $this->at + 2 ] >= '0' && $this->css[ $this->at + 2 ] <= '9';
+			}
+
+			// Otherwise, return false.
+			return false;
+		}
+
+		// U+002E FULL STOP (.).
+		if ( '.' === $this->css[ $this->at ] ) {
+			if ( $this->at + 1 >= $this->length ) {
+				return false;
+			}
+			return $this->css[ $this->at + 1 ] >= '0' && $this->css[ $this->at + 1 ] <= '9';
+		}
+
+		// Digit.
+		if ( $this->css[ $this->at ] >= '0' && $this->css[ $this->at ] <= '9' ) {
+			return true;
+		}
+
+		// Anything else – return false.
+		return false;
+	}
+
+	/**
+	 * Checks if three code points would start an identifier sequence.
+	 *
+	 * This implements the CSS spec's "Check if three code points would start an ident sequence"
+	 * algorithm, which checks the code point at $offset and the following two code points.
+	 *
+	 * NOTE: "Three code points" means three Unicode code points, not three bytes.
+	 * Multi-byte UTF-8 sequences count as single code points.
+	 *
+	 * @see https://www.w3.org/TR/css-syntax-3/#would-start-an-identifier
+	 *
+	 * @param int $offset Byte offset of the first code point to check.
+	 * @return bool
+	 */
+	private function check_if_3_code_points_start_an_ident_sequence( int $offset ): bool {
+		if ( $offset >= $this->length ) {
+			return false;
+		}
+
+		if ( '-' === $this->css[ $offset ] ) {
+			// If the second code point is a U+002D HYPHEN-MINUS (-), return true.
+			// e.g. --custom-property.
+			if ( $offset + 1 < $this->length && '-' === $this->css[ $offset + 1 ] ) {
+				return true;
+			}
+			// Otherwise, check if the second code point is an ident-START code point or valid escape.
+			// Note: After a hyphen, only ident-START code points are valid, NOT digits or hyphens.
+			++$offset;
+		}
+
+		return $this->consume_ident_start_codepoint( $offset ) > 0 || $this->is_valid_escape( $offset );
+	}
+}
diff --git a/components/Encoding/utf8-decoder.php b/components/Encoding/utf8-decoder.php
index 7770440e..e339e710 100644
--- a/components/Encoding/utf8-decoder.php
+++ b/components/Encoding/utf8-decoder.php
@@ -18,6 +18,570 @@
 	define( 'UTF8_DECODER_REJECT', 1 );
 }
 
+/**
+ * Finds spans of valid and invalid UTF-8 bytes in a given string.
+ *
+ * This is a low-level tool to power various UTF-8 functionality.
+ * It scans through a string until it finds invalid byte spans.
+ * When it does this, it does three things:
+ *
+ *  - Assigns `$at` to the position after the last successful code point.
+ *  - Assigns `$invalid_length` to the length of the maximal subpart of
+ *    the invalid bytes starting at `$at`.
+ *  - Returns how many code points were successfully scanned.
+ *
+ * This information is enough to build a number of useful UTF-8 functions.
+ *
+ * Example:
+ *
+ *     // ñ is U+F1, which in `ISO-8859-1`/`latin1`/`Windows-1252`/`cp1252` is 0xF1.
+ *     "Pi\xF1a" === $pineapple = mb_convert_encoding( "Piña", 'Windows-1252', 'UTF-8' );
+ *     $at = $invalid_length = 0;
+ *
+ *     // The first step finds the invalid 0xF1 byte.
+ *     2 === _wp_scan_utf8( $pineapple, $at, $invalid_length );
+ *     $at === 2; $invalid_length === 1;
+ *
+ *     // The second step continues to the end of the string.
+ *     1 === _wp_scan_utf8( $pineapple, $at, $invalid_length );
+ *     $at === 4; $invalid_length === 0;
+ *
+ * Note! While passing an options array here might be convenient from a calling-code standpoint,
+ *       this function is intended to serve as a very low-level foundation upon which to build
+ *       higher level functionality. For the sake of keeping costs explicit all arguments are
+ *       passed directly.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @param string    $bytes             UTF-8 encoded string which might include invalid spans of bytes.
+ * @param int       $at                Where to start scanning.
+ * @param int       $invalid_length    Will be set to how many bytes are to be ignored after `$at`.
+ * @param int|null  $max_bytes         Stop scanning after this many bytes have been seen.
+ * @param int|null  $max_code_points   Stop scanning after this many code points have been seen.
+ * @param bool|null $has_noncharacters Set to indicate if scanned string contained noncharacters.
+ * @return int How many code points were successfully scanned.
+ */
+function _wp_scan_utf8( string $bytes, int &$at, int &$invalid_length, ?int $max_bytes = null, ?int $max_code_points = null, ?bool &$has_noncharacters = null ): int {
+	$byte_length       = strlen( $bytes );
+	$end               = min( $byte_length, $at + ( $max_bytes ?? PHP_INT_MAX ) );
+	$invalid_length    = 0;
+	$count             = 0;
+	$max_count         = $max_code_points ?? PHP_INT_MAX;
+	$has_noncharacters = false;
+
+	for ( $i = $at; $i < $end && $count <= $max_count; $i++ ) {
+		/*
+		 * Quickly skip past US-ASCII bytes, all of which are valid UTF-8.
+		 *
+		 * This optimization step improves the speed from 10x to 100x
+		 * depending on whether the JIT has optimized the function.
+		 */
+		$ascii_byte_count = strspn(
+			$bytes,
+			"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" .
+			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" .
+			" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f",
+			$i,
+			$end - $i
+		);
+
+		if ( $count + $ascii_byte_count >= $max_count ) {
+			$at    = $i + ( $max_count - $count );
+			$count = $max_count;
+			return $count;
+		}
+
+		$count += $ascii_byte_count;
+		$i     += $ascii_byte_count;
+
+		if ( $i >= $end ) {
+			$at = $end;
+			return $count;
+		}
+
+		/**
+		 * The above fast-track handled all single-byte UTF-8 characters. What
+		 * follows MUST be a multibyte sequence otherwise there’s invalid UTF-8.
+		 *
+		 * Therefore everything past here is checking those multibyte sequences.
+		 *
+		 * It may look like there’s a need to check against the max bytes here,
+		 * but since each match of a single character returns, this functions will
+		 * bail already if crossing the max-bytes threshold. This function SHALL
+		 * NOT return in the middle of a multi-byte character, so if a character
+		 * falls on each side of the max bytes, the entire character will be scanned.
+		 *
+		 * Because it’s possible that there are truncated characters, the use of
+		 * the null-coalescing operator with "\xC0" is a convenience for skipping
+		 * length checks on every continuation bytes. This works because 0xC0 is
+		 * always invalid in a UTF-8 string, meaning that if the string has been
+		 * truncated, it will find 0xC0 and reject as invalid UTF-8.
+		 *
+		 * > [The following table] lists all of the byte sequences that are well-formed
+		 * > in UTF-8. A range of byte values such as A0..BF indicates that any byte
+		 * > from A0 to BF (inclusive) is well-formed in that position. Any byte value
+		 * > outside of the ranges listed is ill-formed.
+		 *
+		 * > Table 3-7. Well-Formed UTF-8 Byte Sequences
+		 *  ╭─────────────────────┬────────────┬──────────────┬─────────────┬──────────────╮
+		 *  │ Code Points         │ First Byte │ Second Byte  │ Third Byte  │ Fourth Byte  │
+		 *  ├─────────────────────┼────────────┼──────────────┼─────────────┼──────────────┤
+		 *  │ U+0000..U+007F      │ 00..7F     │              │             │              │
+		 *  │ U+0080..U+07FF      │ C2..DF     │ 80..BF       │             │              │
+		 *  │ U+0800..U+0FFF      │ E0         │ A0..BF       │ 80..BF      │              │
+		 *  │ U+1000..U+CFFF      │ E1..EC     │ 80..BF       │ 80..BF      │              │
+		 *  │ U+D000..U+D7FF      │ ED         │ 80..9F       │ 80..BF      │              │
+		 *  │ U+E000..U+FFFF      │ EE..EF     │ 80..BF       │ 80..BF      │              │
+		 *  │ U+10000..U+3FFFF    │ F0         │ 90..BF       │ 80..BF      │ 80..BF       │
+		 *  │ U+40000..U+FFFFF    │ F1..F3     │ 80..BF       │ 80..BF      │ 80..BF       │
+		 *  │ U+100000..U+10FFFF  │ F4         │ 80..8F       │ 80..BF      │ 80..BF       │
+		 *  ╰─────────────────────┴────────────┴──────────────┴─────────────┴──────────────╯
+		 *
+		 * @see https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G27506
+		 */
+
+		// Valid two-byte code points.
+		$b1 = ord( $bytes[ $i ] );
+		$b2 = ord( $bytes[ $i + 1 ] ?? "\xC0" );
+
+		if ( $b1 >= 0xC2 && $b1 <= 0xDF && $b2 >= 0x80 && $b2 <= 0xBF ) {
+			++$count;
+			++$i;
+			continue;
+		}
+
+		// Valid three-byte code points.
+		$b3 = ord( $bytes[ $i + 2 ] ?? "\xC0" );
+
+		if ( $b3 < 0x80 || $b3 > 0xBF ) {
+			goto invalid_utf8;
+		}
+
+		if (
+			( 0xE0 === $b1 && $b2 >= 0xA0 && $b2 <= 0xBF ) ||
+			( $b1 >= 0xE1 && $b1 <= 0xEC && $b2 >= 0x80 && $b2 <= 0xBF ) ||
+			( 0xED === $b1 && $b2 >= 0x80 && $b2 <= 0x9F ) ||
+			( $b1 >= 0xEE && $b1 <= 0xEF && $b2 >= 0x80 && $b2 <= 0xBF )
+		) {
+			++$count;
+			$i += 2;
+
+			// Covers the range U+FDD0–U+FDEF, U+FFFE, U+FFFF.
+			if ( 0xEF === $b1 ) {
+				$has_noncharacters |= (
+					( 0xB7 === $b2 && $b3 >= 0x90 && $b3 <= 0xAF ) ||
+					( 0xBF === $b2 && ( 0xBE === $b3 || 0xBF === $b3 ) )
+				);
+			}
+
+			continue;
+		}
+
+		// Valid four-byte code points.
+		$b4 = ord( $bytes[ $i + 3 ] ?? "\xC0" );
+
+		if ( $b4 < 0x80 || $b4 > 0xBF ) {
+			goto invalid_utf8;
+		}
+
+		if (
+			( 0xF0 === $b1 && $b2 >= 0x90 && $b2 <= 0xBF ) ||
+			( $b1 >= 0xF1 && $b1 <= 0xF3 && $b2 >= 0x80 && $b2 <= 0xBF ) ||
+			( 0xF4 === $b1 && $b2 >= 0x80 && $b2 <= 0x8F )
+		) {
+			++$count;
+			$i += 3;
+
+			// Covers U+1FFFE, U+1FFFF, U+2FFFE, U+2FFFF, …, U+10FFFE, U+10FFFF.
+			$has_noncharacters |= (
+				( 0x0F === ( $b2 & 0x0F ) ) &&
+				0xBF === $b3 &&
+				( 0xBE === $b4 || 0xBF === $b4 )
+			);
+
+			continue;
+		}
+
+		/**
+		 * When encountering invalid byte sequences, Unicode suggests finding the
+		 * maximal subpart of a text and replacing that subpart with a single
+		 * replacement character.
+		 *
+		 * > This practice is more secure because it does not result in the
+		 * > conversion consuming parts of valid sequences as though they were
+		 * > invalid. It also guarantees at least one replacement character will
+		 * > occur for each instance of an invalid sequence in the original text.
+		 * > Furthermore, this practice can be defined consistently for better
+		 * > interoperability between different implementations of conversion.
+		 *
+		 * @see https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-5/#G40630
+		 */
+		invalid_utf8:
+		$at             = $i;
+		$invalid_length = 1;
+
+		// Single-byte and two-byte characters.
+		if ( ( 0x00 === ( $b1 & 0x80 ) ) || ( 0xC0 === ( $b1 & 0xE0 ) ) ) {
+			return $count;
+		}
+
+		$b2 = ord( $bytes[ $i + 1 ] ?? "\xC0" );
+		$b3 = ord( $bytes[ $i + 2 ] ?? "\xC0" );
+
+		// Find the maximal subpart and skip past it.
+		if ( 0xE0 === ( $b1 & 0xF0 ) ) {
+			// Three-byte characters.
+			$b2_valid = (
+				( 0xE0 === $b1 && $b2 >= 0xA0 && $b2 <= 0xBF ) ||
+				( $b1 >= 0xE1 && $b1 <= 0xEC && $b2 >= 0x80 && $b2 <= 0xBF ) ||
+				( 0xED === $b1 && $b2 >= 0x80 && $b2 <= 0x9F ) ||
+				( $b1 >= 0xEE && $b1 <= 0xEF && $b2 >= 0x80 && $b2 <= 0xBF )
+			);
+
+			$invalid_length = min( $end - $i, $b2_valid ? 2 : 1 );
+			return $count;
+		} elseif ( 0xF0 === ( $b1 & 0xF8 ) ) {
+			// Four-byte characters.
+			$b2_valid = (
+				( 0xF0 === $b1 && $b2 >= 0x90 && $b2 <= 0xBF ) ||
+				( $b1 >= 0xF1 && $b1 <= 0xF3 && $b2 >= 0x80 && $b2 <= 0xBF ) ||
+				( 0xF4 === $b1 && $b2 >= 0x80 && $b2 <= 0x8F )
+			);
+
+			$b3_valid = $b3 >= 0x80 && $b3 <= 0xBF;
+
+			$invalid_length = min( $end - $i, $b2_valid ? ( $b3_valid ? 3 : 2 ) : 1 );
+			return $count;
+		}
+
+		return $count;
+	}
+
+	$at = $i;
+	return $count;
+}
+
+/**
+ * Fallback mechanism for safely validating UTF-8 bytes.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see wp_is_valid_utf8()
+ *
+ * @param string $bytes String which might contain text encoded as UTF-8.
+ * @return bool Whether the provided bytes can decode as valid UTF-8.
+ */
+function _wp_is_valid_utf8_fallback( string $bytes ): bool {
+	$bytes_length = strlen( $bytes );
+	if ( 0 === $bytes_length ) {
+		return true;
+	}
+
+	$next_byte_at   = 0;
+	$invalid_length = 0;
+
+	_wp_scan_utf8( $bytes, $next_byte_at, $invalid_length );
+
+	return $bytes_length === $next_byte_at && 0 === $invalid_length;
+}
+
+/**
+ * Fallback mechanism for replacing invalid spans of UTF-8 bytes.
+ *
+ * Example:
+ *
+ *     'Pi�a' === _wp_scrub_utf8_fallback( "Pi\xF1a" ); // “ñ” is 0xF1 in Windows-1252.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see wp_scrub_utf8()
+ *
+ * @param string $bytes UTF-8 encoded string which might contain spans of invalid bytes.
+ * @return string Input string with spans of invalid bytes swapped with the replacement character.
+ */
+function _wp_scrub_utf8_fallback( string $bytes ): string {
+	$bytes_length   = strlen( $bytes );
+	$next_byte_at   = 0;
+	$was_at         = 0;
+	$invalid_length = 0;
+	$scrubbed       = '';
+
+	while ( $next_byte_at <= $bytes_length ) {
+		_wp_scan_utf8( $bytes, $next_byte_at, $invalid_length );
+
+		if ( $next_byte_at >= $bytes_length ) {
+			if ( 0 === $was_at ) {
+				return $bytes;
+			}
+
+			return $scrubbed . substr( $bytes, $was_at, $next_byte_at - $was_at - $invalid_length );
+		}
+
+		$scrubbed .= substr( $bytes, $was_at, $next_byte_at - $was_at );
+		$scrubbed .= "\u{FFFD}";
+
+		$next_byte_at += $invalid_length;
+		$was_at        = $next_byte_at;
+	}
+
+	return $scrubbed;
+}
+
+/**
+ * Returns how many code points are found in the given UTF-8 string.
+ *
+ * Invalid spans of bytes count as a single code point according
+ * to the maximal subpart rule. This function is a fallback method
+ * for calling `mb_strlen( $text, 'UTF-8' )`.
+ *
+ * When negative values are provided for the byte offsets or length,
+ * this will always report zero code points.
+ *
+ * Example:
+ *
+ *     4  === _wp_utf8_codepoint_count( 'text' );
+ *
+ *     // Groups are 'test', "\x90" as '�', 'wp', "\xE2\x80" as '�', "\xC0" as '�', and 'test'.
+ *     13 === _wp_utf8_codepoint_count( "test\x90wp\xE2\x80\xC0test" );
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @param string $text            Count code points in this string.
+ * @param ?int   $byte_offset     Start counting after this many bytes in `$text`. Must be positive.
+ * @param ?int   $max_byte_length Optional. Stop counting after having scanned past this many bytes.
+ *                                Default is to scan until the end of the string. Must be positive.
+ * @return int How many code points were found.
+ */
+function _wp_utf8_codepoint_count( string $text, ?int $byte_offset = 0, ?int $max_byte_length = PHP_INT_MAX ): int {
+	if ( $byte_offset < 0 ) {
+		return 0;
+	}
+
+	$count           = 0;
+	$at              = $byte_offset;
+	$end             = strlen( $text );
+	$invalid_length  = 0;
+	$max_byte_length = min( $end - $at, $max_byte_length );
+
+	while ( $at < $end && ( $at - $byte_offset ) < $max_byte_length ) {
+		$count += _wp_scan_utf8( $text, $at, $invalid_length, $max_byte_length - ( $at - $byte_offset ) );
+		$count += $invalid_length > 0 ? 1 : 0;
+		$at    += $invalid_length;
+	}
+
+	return $count;
+}
+
+/**
+ * Given a starting offset within a string and a maximum number of code points,
+ * return how many bytes are occupied by the span of characters.
+ *
+ * Invalid spans of bytes count as a single code point according to the maximal
+ * subpart rule. This function is a fallback method for calling
+ * `strlen( mb_substr( substr( $text, $at ), 0, $max_code_points ) )`.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @param string $text              Count bytes of span in this text.
+ * @param int    $byte_offset       Start counting at this byte offset.
+ * @param int    $max_code_points   Stop counting after this many code points have been seen,
+ *                                  or at the end of the string.
+ * @param ?int   $found_code_points Optional. Will be set to number of found code points in
+ *                                  span, as this might be smaller than the maximum count if
+ *                                  the string is not long enough.
+ * @return int Number of bytes spanned by the code points.
+ */
+function _wp_utf8_codepoint_span( string $text, int $byte_offset, int $max_code_points, ?int &$found_code_points = 0 ): int {
+	$was_at            = $byte_offset;
+	$invalid_length    = 0;
+	$end               = strlen( $text );
+	$found_code_points = 0;
+
+	while ( $byte_offset < $end && $found_code_points < $max_code_points ) {
+		$needed      = $max_code_points - $found_code_points;
+		$chunk_count = _wp_scan_utf8( $text, $byte_offset, $invalid_length, null, $needed );
+
+		$found_code_points += $chunk_count;
+
+		// Invalid spans only convey one code point count regardless of how long they are.
+		if ( 0 !== $invalid_length && $found_code_points < $max_code_points ) {
+			++$found_code_points;
+			$byte_offset += $invalid_length;
+		}
+	}
+
+	return $byte_offset - $was_at;
+}
+
+/**
+ * Fallback support for determining if a string contains Unicode noncharacters.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see \wp_has_noncharacters()
+ *
+ * @param string $text Are there noncharacters in this string?
+ * @return bool Whether noncharacters were found in the string.
+ */
+function _wp_has_noncharacters_fallback( string $text ): bool {
+	$at                = 0;
+	$invalid_length    = 0;
+	$has_noncharacters = false;
+	$end               = strlen( $text );
+
+	while ( $at < $end && ! $has_noncharacters ) {
+		_wp_scan_utf8( $text, $at, $invalid_length, null, null, $has_noncharacters );
+		$at += $invalid_length;
+	}
+
+	return $has_noncharacters;
+}
+
+/**
+ * Converts a string from ISO-8859-1 to UTF-8, maintaining backwards compatibility
+ * with the deprecated function from the PHP standard library.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see \utf8_encode()
+ *
+ * @param string $iso_8859_1_text Text treated as ISO-8859-1 (latin1) bytes.
+ * @return string Text converted into UTF-8.
+ */
+function _wp_utf8_encode_fallback( $iso_8859_1_text ) {
+	$iso_8859_1_text = (string) $iso_8859_1_text;
+	$at              = 0;
+	$was_at          = 0;
+	$end             = strlen( $iso_8859_1_text );
+	$utf8            = '';
+
+	while ( $at < $end ) {
+		// US-ASCII bytes are identical in ISO-8859-1 and UTF-8. These are 0x00–0x7F.
+		$ascii_byte_count = strspn(
+			$iso_8859_1_text,
+			"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" .
+			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" .
+			" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f",
+			$at
+		);
+
+		if ( $ascii_byte_count > 0 ) {
+			$at += $ascii_byte_count;
+			continue;
+		}
+
+		// All other bytes transform into two-byte UTF-8 sequences.
+		$code_point = ord( $iso_8859_1_text[ $at ] );
+		$byte1      = chr( 0xC0 | ( $code_point >> 6 ) );
+		$byte2      = chr( 0x80 | ( $code_point & 0x3F ) );
+
+		$utf8 .= substr( $iso_8859_1_text, $was_at, $at - $was_at );
+		$utf8 .= "{$byte1}{$byte2}";
+
+		++$at;
+		$was_at = $at;
+	}
+
+	if ( 0 === $was_at ) {
+		return $iso_8859_1_text;
+	}
+
+	$utf8 .= substr( $iso_8859_1_text, $was_at );
+	return $utf8;
+}
+
+/**
+ * Converts a string from UTF-8 to ISO-8859-1, maintaining backwards compatibility
+ * with the deprecated function from the PHP standard library.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see utf8_decode()
+ *
+ * @param string $utf8_text Text treated as UTF-8 bytes.
+ * @return string Text converted into ISO-8859-1.
+ */
+function _wp_utf8_decode_fallback( $utf8_text ) {
+	$utf8_text       = (string) $utf8_text;
+	$at              = 0;
+	$was_at          = 0;
+	$end             = strlen( $utf8_text );
+	$iso_8859_1_text = '';
+
+	while ( $at < $end ) {
+		// US-ASCII bytes are identical in ISO-8859-1 and UTF-8. These are 0x00–0x7F.
+		$ascii_byte_count = strspn(
+			$utf8_text,
+			"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" .
+			"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" .
+			" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f",
+			$at
+		);
+
+		if ( $ascii_byte_count > 0 ) {
+			$at += $ascii_byte_count;
+			continue;
+		}
+
+		$next_at        = $at;
+		$invalid_length = 0;
+		$found          = _wp_scan_utf8( $utf8_text, $next_at, $invalid_length, null, 1 );
+		$span_length    = $next_at - $at;
+		$next_byte      = '?';
+
+		if ( 1 !== $found ) {
+			if ( $invalid_length > 0 ) {
+				$next_byte = '';
+				goto flush_sub_part;
+			}
+
+			break;
+		}
+
+		// All convertible code points are two-bytes long.
+		$byte1 = ord( $utf8_text[ $at ] );
+		if ( 0xC0 !== ( $byte1 & 0xE0 ) ) {
+			goto flush_sub_part;
+		}
+
+		// All convertible code points are not greater than U+FF.
+		$byte2      = ord( $utf8_text[ $at + 1 ] );
+		$code_point = ( ( $byte1 & 0x1F ) << 6 ) | ( ( $byte2 & 0x3F ) );
+		if ( $code_point > 0xFF ) {
+			goto flush_sub_part;
+		}
+
+		$next_byte = chr( $code_point );
+
+		flush_sub_part:
+		$iso_8859_1_text .= substr( $utf8_text, $was_at, $at - $was_at );
+		$iso_8859_1_text .= $next_byte;
+		$at              += $span_length;
+		$was_at           = $at;
+
+		if ( $invalid_length > 0 ) {
+			$iso_8859_1_text .= '?';
+			$at              += $invalid_length;
+			$was_at           = $at;
+		}
+	}
+
+	if ( 0 === $was_at ) {
+		return $utf8_text;
+	}
+
+	$iso_8859_1_text .= substr( $utf8_text, $was_at );
+	return $iso_8859_1_text;
+}
+
 /**
  * Indicates if a given byte stream represents valid UTF-8.
  *