diff --git a/features/empty.yml b/features/empty.yml
new file mode 100644
index 00000000000..35c4e481c5a
--- /dev/null
+++ b/features/empty.yml
@@ -0,0 +1,9 @@
+name: :empty
+description: The `:empty` CSS pseudo-class matches elements without child elements.
+spec: https://drafts.csswg.org/selectors-4/#the-empty-pseudo
+group: selectors
+status:
+  compute_from: css.selectors.empty
+compat_features:
+  - css.selectors.empty
+  - css.selectors.empty.matches_whitespace
diff --git a/features/empty.yml.dist b/features/empty.yml.dist
new file mode 100644
index 00000000000..f779287f91f
--- /dev/null
+++ b/features/empty.yml.dist
@@ -0,0 +1,33 @@
+# Generated from: empty.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "3.1"
+    safari_ios: "2"
+compat_features:
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "1"
+  #   firefox_android: "4"
+  #   safari: "3.1"
+  #   safari_ios: "2"
+  - css.selectors.empty
+
+  # baseline: false
+  # support: {}
+  - css.selectors.empty.matches_whitespace
diff --git a/features/input-selectors.yml b/features/input-selectors.yml
new file mode 100644
index 00000000000..7d3923707fe
--- /dev/null
+++ b/features/input-selectors.yml
@@ -0,0 +1,12 @@
+name: Input selectors
+description: The `:checked`, `:disabled`, and `:enabled` CSS pseudo-classes match form elements based on their state.
+spec:
+  - https://drafts.csswg.org/selectors-4/#checked
+  - https://drafts.csswg.org/selectors-4/#enableddisabled
+group:
+  - forms
+  - selectors
+compat_features:
+  - css.selectors.checked
+  - css.selectors.disabled
+  - css.selectors.enabled
diff --git a/features/input-selectors.yml.dist b/features/input-selectors.yml.dist
new file mode 100644
index 00000000000..d4baecf25d6
--- /dev/null
+++ b/features/input-selectors.yml.dist
@@ -0,0 +1,19 @@
+# Generated from: input-selectors.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "3.1"
+    safari_ios: "2"
+compat_features:
+  - css.selectors.checked
+  - css.selectors.disabled
+  - css.selectors.enabled
diff --git a/features/lang.yml b/features/lang.yml
new file mode 100644
index 00000000000..fb2f5136c6f
--- /dev/null
+++ b/features/lang.yml
@@ -0,0 +1,10 @@
+name: :lang()
+description: The `:lang()` CSS functional pseudo-class matches elements based on their content language.
+spec: https://drafts.csswg.org/selectors-4/#the-lang-pseudo
+group: selectors
+status:
+  compute_from: css.selectors.lang
+compat_features:
+  - css.selectors.lang
+  - css.selectors.lang.argument_list
+  - css.selectors.lang.wildcards
diff --git a/features/lang.yml.dist b/features/lang.yml.dist
new file mode 100644
index 00000000000..4420665b2f6
--- /dev/null
+++ b/features/lang.yml.dist
@@ -0,0 +1,38 @@
+# Generated from: lang.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "3.1"
+    safari_ios: "2"
+compat_features:
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "1"
+  #   firefox_android: "4"
+  #   safari: "3.1"
+  #   safari_ios: "2"
+  - css.selectors.lang
+
+  # baseline: false
+  # support:
+  #   firefox: "114"
+  #   firefox_android: "114"
+  #   safari: "9"
+  #   safari_ios: "9"
+  - css.selectors.lang.argument_list
+  - css.selectors.lang.wildcards
diff --git a/features/not.yml b/features/not.yml
new file mode 100644
index 00000000000..583be4e1f2b
--- /dev/null
+++ b/features/not.yml
@@ -0,0 +1,8 @@
+name: :not
+description: The `:not()` functional pseudo-class matches elements that do not match the selectors in its argument.
+spec: https://drafts.csswg.org/selectors-4/#negation
+caniuse: css-not-sel-list
+group: selectors
+compat_features:
+  - css.selectors.not
+  - css.selectors.not.selector_list
diff --git a/features/not.yml.dist b/features/not.yml.dist
new file mode 100644
index 00000000000..941ef78c1df
--- /dev/null
+++ b/features/not.yml.dist
@@ -0,0 +1,42 @@
+# Generated from: not.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2021-01-21
+  baseline_high_date: 2023-07-21
+  support:
+    chrome: "88"
+    chrome_android: "88"
+    edge: "88"
+    firefox: "84"
+    firefox_android: "84"
+    safari: "9"
+    safari_ios: "9"
+compat_features:
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "1"
+  #   firefox_android: "4"
+  #   safari: "3.1"
+  #   safari_ios: "2"
+  - css.selectors.not
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2021-01-21
+  # baseline_high_date: 2023-07-21
+  # support:
+  #   chrome: "88"
+  #   chrome_android: "88"
+  #   edge: "88"
+  #   firefox: "84"
+  #   firefox_android: "84"
+  #   safari: "9"
+  #   safari_ios: "9"
+  - css.selectors.not.selector_list
diff --git a/features/root.yml b/features/root.yml
new file mode 100644
index 00000000000..35177713489
--- /dev/null
+++ b/features/root.yml
@@ -0,0 +1,6 @@
+name: :root
+description: The `:root` pseudo-class matches the root element of the document, usually the `<html>` element.
+spec: https://drafts.csswg.org/selectors-4/#the-root-pseudo
+group: selectors
+compat_features:
+  - css.selectors.root
diff --git a/features/root.yml.dist b/features/root.yml.dist
new file mode 100644
index 00000000000..a60c93287d3
--- /dev/null
+++ b/features/root.yml.dist
@@ -0,0 +1,17 @@
+# Generated from: root.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "1"
+    safari_ios: "1"
+compat_features:
+  - css.selectors.root
diff --git a/features/target.yml b/features/target.yml
new file mode 100644
index 00000000000..a64fe301163
--- /dev/null
+++ b/features/target.yml
@@ -0,0 +1,6 @@
+name: :target
+description: The `:target` CSS pseudo-class matches the element with an ID matching the URL fragment.
+spec: https://drafts.csswg.org/selectors-4/#the-target-pseudo
+group: selectors
+compat_features:
+  - css.selectors.target
diff --git a/features/target.yml.dist b/features/target.yml.dist
new file mode 100644
index 00000000000..bb4d94e27b8
--- /dev/null
+++ b/features/target.yml.dist
@@ -0,0 +1,17 @@
+# Generated from: target.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "1.3"
+    safari_ios: "2"
+compat_features:
+  - css.selectors.target
diff --git a/features/user-action-pseudos.yml b/features/user-action-pseudos.yml
new file mode 100644
index 00000000000..23200dcae47
--- /dev/null
+++ b/features/user-action-pseudos.yml
@@ -0,0 +1,12 @@
+name: User action pseudo-classes
+description: The `:active`, `:focus`, and `:hover` CSS pseudo-classes match elements based on how users are interacting with them.
+spec:
+  - https://drafts.csswg.org/selectors-4/#the-hover-pseudo
+  - https://drafts.csswg.org/selectors-4/#the-active-pseudo
+  - https://drafts.csswg.org/selectors-4/#the-focus-pseudo
+group: selectors
+compat_features:
+  - css.selectors.active
+  - css.selectors.active.non_a_elements
+  - css.selectors.focus
+  - css.selectors.hover
diff --git a/features/user-action-pseudos.yml.dist b/features/user-action-pseudos.yml.dist
new file mode 100644
index 00000000000..9cb8916992d
--- /dev/null
+++ b/features/user-action-pseudos.yml.dist
@@ -0,0 +1,44 @@
+# Generated from: user-action-pseudos.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: high
+  baseline_low_date: 2015-07-29
+  baseline_high_date: 2018-01-29
+  support:
+    chrome: "1"
+    chrome_android: "18"
+    edge: "12"
+    firefox: "1"
+    firefox_android: "4"
+    safari: "2"
+    safari_ios: "1"
+compat_features:
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "1"
+  #   firefox_android: "4"
+  #   safari: "1"
+  #   safari_ios: "1"
+  - css.selectors.active
+  - css.selectors.active.non_a_elements
+  - css.selectors.focus
+
+  # ⬇️ Same status as overall feature ⬇️
+  # baseline: high
+  # baseline_low_date: 2015-07-29
+  # baseline_high_date: 2018-01-29
+  # support:
+  #   chrome: "1"
+  #   chrome_android: "18"
+  #   edge: "12"
+  #   firefox: "1"
+  #   firefox_android: "4"
+  #   safari: "2"
+  #   safari_ios: "1"
+  - css.selectors.hover