Fixed the parser to handle angle bracket type syntax (e.g., <number>, <string>, <color>) in CSS attr() functions.

[mohamedmansour]

Changes

• Added angle_bracket_value rule to parse <type_name> syntax
• Restricted to function arguments only (not general CSS values)
• Includes test for various attribute angles

Spec Reference

CSS Values and Units Module Level 5 § 8.7 attr() notation

Examples

.foo {
  --x: attr(foo type(<number>), 0);
  width: attr(data-width <length>, 100px);
  color: attr(data-color <color>, blue);
}

Testing

• All existing tests pass (41/41)
• Added new test case covering multiple type syntaxes
• Verified angle brackets properly rejected outside function arguments

Fixes #88

[mohamedmansour]

@amaanq I added support for the CSS spec for angled brackets, don't know if I was supposed to commit the parse.c and grammar.json