Passes tests starting point

Author: jacobcassidy

src/vscode-css/grammars/css.cson

@@ -983,7 +983,7 @@
       }
       # Colours
       {
-        'begin': '(?i)(?<![\\w-])(rgba?|rgb|hsla?|hsl|hwb|lab|oklab|lch|oklch|color)(\\()'
+        'begin': '(?i)(?<![\\w-])(rgba?|rgb|hsla?|hsl|hwb|lab|oklab|lch|oklch|color|light-dark)(\\()'
         'beginCaptures':
           '1':
             'name': 'support.function.misc.css'
@@ -2084,7 +2084,7 @@
                 | \\\\(?:[0-9a-fA-F]{1,6}|.)         # - Escape sequence
               )*
               (?:                                    # Invalid punctuation
-                [!"'%&(*;<?@^`|\\]}]                 # - NOTE: We exempt `)` from the list of checked
+                [!"'%(*;<?@^`|\\]}]                  # - NOTE: We exempt `)` from the list of checked
                 |                                    #   symbols to avoid matching `:not(.invalid)`
                 / (?!\\*)                            # - Avoid invalidating the start of a comment
               )+

syntaxes/css.tmLanguage.json

@@ -1019,7 +1019,7 @@
 					]
 				},
 				{
-					"begin": "(?i)(?<![\\w-])(rgba?|rgb|hsla?|hsl|hwb|lab|oklab|lch|oklch|color)(\\()",
+					"begin": "(?i)(?<![\\w-])(rgba?|rgb|hsla?|hsl|hwb|lab|oklab|lch|oklch|color|light-dark)(\\()",
 					"beginCaptures": {
 						"1": {
 							"name": "support.function.misc.css"
@@ -1597,7 +1597,18 @@
 					"name": "entity.name.tag.css"
 				},
 				{
-					"include": "#property-names"
+					"match": "(?x) (?<![\\w-])\n--\n(?:[-a-zA-Z_]    | [^\\x00-\\x7F])     # First letter\n(?:[-a-zA-Z0-9_] | [^\\x00-\\x7F]      # Remainder of identifier\n  |\\\\(?:[0-9a-fA-F]{1,6}|.)\n)*",
+					"name": "variable.css"
+				},
+				{
+					"begin": "(?<![-a-zA-Z])(?=[-a-zA-Z])",
+					"end": "$|(?![-a-zA-Z])",
+					"name": "meta.property-name.css",
+					"patterns": [
+						{
+							"include": "#property-names"
+						}
+					]
 				},
 				{
 					"include": "#selector-innards"
@@ -1862,7 +1873,7 @@
 							]
 						}
 					},
-					"match": "(?x) (?<![@\\w-])\n([.\\#])\n# Invalid identifier\n(\n  (?:\n    # Starts with ASCII digits, with possible hyphen preceding it\n    -?[0-9]\n    |\n    # Consists of a hyphen only\n    -                                      # Terminated by either:\n    (?= $                                  # - End-of-line\n      | [\\s,.\\#)\\[:{>+~|&]               # - Followed by another selector\n      | /\\*                               # - Followed by a block comment\n    )\n    |\n    # Name contains unescaped ASCII symbol\n    (?:                                    # Check for acceptable preceding characters\n        [-a-zA-Z_0-9]|[^\\x00-\\x7F]       # - Valid selector character\n      | \\\\(?:[0-9a-fA-F]{1,6}|.)         # - Escape sequence\n    )*\n    (?:                                    # Invalid punctuation\n      [!\"'%&(*;<?@^`|\\]}]                 # - NOTE: We exempt `)` from the list of checked\n      |                                    #   symbols to avoid matching `:not(.invalid)`\n      / (?!\\*)                            # - Avoid invalidating the start of a comment\n    )+\n  )\n  # Mark remainder of selector invalid\n  (?: [-a-zA-Z_0-9]|[^\\x00-\\x7F]         # - Otherwise valid identifier characters\n    | \\\\(?:[0-9a-fA-F]{1,6}|.)           # - Escape sequence\n  )*\n)",
+					"match": "(?x) (?<![@\\w-])\n([.\\#])\n# Invalid identifier\n(\n  (?:\n    # Starts with ASCII digits, with possible hyphen preceding it\n    -?[0-9]\n    |\n    # Consists of a hyphen only\n    -                                      # Terminated by either:\n    (?= $                                  # - End-of-line\n      | [\\s,.\\#)\\[:{>+~|&]               # - Followed by another selector\n      | /\\*                               # - Followed by a block comment\n    )\n    |\n    # Name contains unescaped ASCII symbol\n    (?:                                    # Check for acceptable preceding characters\n        [-a-zA-Z_0-9]|[^\\x00-\\x7F]       # - Valid selector character\n      | \\\\(?:[0-9a-fA-F]{1,6}|.)         # - Escape sequence\n    )*\n    (?:                                    # Invalid punctuation\n      [!\"'%(*;<?@^`|\\]}]                  # - NOTE: We exempt `)` from the list of checked\n      |                                    #   symbols to avoid matching `:not(.invalid)`\n      / (?!\\*)                            # - Avoid invalidating the start of a comment\n    )+\n  )\n  # Mark remainder of selector invalid\n  (?: [-a-zA-Z_0-9]|[^\\x00-\\x7F]         # - Otherwise valid identifier characters\n    | \\\\(?:[0-9a-fA-F]{1,6}|.)           # - Escape sequence\n  )*\n)",
 					"name": "invalid.illegal.bad-identifier.css"
 				},
 				{