diff --git a/css/syntaxes.json b/css/syntaxes.json
index 1a6e286b9..aa1191d27 100644
--- a/css/syntaxes.json
+++ b/css/syntaxes.json
@@ -123,7 +123,7 @@
     "syntax": "<url>"
   },
   "color": {
-    "syntax": "<rgb()> | <rgba()> | <hsl()> | <hsla()> | <hwb()> | <lab()> | <lch()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>"
+    "syntax": "<rgb()> | <rgba()> | <hsl()> | <hsla()> | <hwb()> | <lab()> | <lch()> | <light-dark()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>"
   },
   "color-stop": {
     "syntax": "<color-stop-length> | <color-stop-angle>"
@@ -425,6 +425,9 @@
   "length-percentage": {
     "syntax": "<length> | <percentage>"
   },
+  "light-dark()": {
+    "syntax": "light-dark( <color>, <color> )"
+  },
   "line-names": {
     "syntax": "'[' <custom-ident>* ']'"
   },