From b2a03534cc3e5ce4de3b2fe83c8cb668d5ec8b95 Mon Sep 17 00:00:00 2001
From: Hugo Peek <hugo@fractal-farming.com>
Date: Sat, 17 Jun 2023 07:37:00 +0000
Subject: [PATCH 1/2] Ignore CSS variables

---
 src/CssLint/Linter.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/CssLint/Linter.php b/src/CssLint/Linter.php
index 53b9828..88c7b81 100644
--- a/src/CssLint/Linter.php
+++ b/src/CssLint/Linter.php
@@ -386,9 +386,15 @@ protected function lintPropertyNameChar(string $sChar): ?bool
         }
 
         if ($sChar === ':') {
-            // Check if property name exists
             $sPropertyName = trim($this->getContextContent());
 
+            // Ignore CSS variables (names starting with --)
+            if (substr($sPropertyName, 0, 2) === '--') {
+                $this->setContext(self::CONTEXT_PROPERTY_CONTENT);
+                return true;
+            }
+            
+            // Check if property name exists
             if (!$this->getCssLintProperties()->propertyExists($sPropertyName)) {
                 $this->addError('Unknown CSS property "' . $sPropertyName . '"');
             }

From 0ad42300d4e724931d5501e341bb0c9f6995792e Mon Sep 17 00:00:00 2001
From: Hugo Peek <hugo@fractal-farming.com>
Date: Sat, 17 Jun 2023 07:42:42 +0000
Subject: [PATCH 2/2] Add CSS variable to valid.css test file

---
 tests/_files/valid.css | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tests/_files/valid.css b/tests/_files/valid.css
index b8e58d8..fb399c3 100644
--- a/tests/_files/valid.css
+++ b/tests/_files/valid.css
@@ -1,4 +1,8 @@
-.button.drodown::after {
+:root {
+  --border-radius: 3px;
+}
+
+.button.dropdown::after {
   display: block;
   width: 0;
   height: 0;
@@ -7,6 +11,7 @@
   border-bottom-width: 0;
   border-top-style: solid;
   border-color: #fefefe transparent transparent;
+  border-radius: var(--border-radius);
   position: relative;
   top: 0.4em;
   display: inline-block;