[bartveneman]

Summary

This PR updates the CSS parser to correctly handle nested at-rules within @font-feature-values and @page blocks, rather than treating their contents as declarations only.

Key Changes

• Updated DECLARATION_AT_RULES set: Removed font-feature-values and page from the set of at-rules that only contain declarations, allowing them to have nested at-rules as children
• Added feature-specific at-rules: Added all CSS feature value descriptors (styleset, stylistic, character-variant, swash, ornaments, annotation) to DECLARATION_AT_RULES since these are nested within @font-feature-values and contain only declarations
• Added page margin at-rules: Added all CSS page margin box at-rules (top-left-corner, top-left, top-center, etc.) to DECLARATION_AT_RULES since these are nested within @page and contain only declarations
• Added comprehensive test coverage: Added two new test cases validating:
  • @font-feature-values with nested @styleset and @swash at-rules
  • @page with mixed declarations and nested margin at-rules (@top-left, @bottom-right-corner)

Implementation Details

The parser now correctly distinguishes between at-rules that can contain nested at-rules (@font-feature-values, @page) and at-rules that only contain declarations (the feature descriptors and margin boxes). This allows proper AST construction for these CSS constructs while maintaining backward compatibility with existing parsing logic.

https://claude.ai/code/session_01BDQgvjjtLygov1cCyBRKTc

[github-actions]

⚠️ Package Size Increase

📦 Package	📏 Base Size	📏 Source Size	📈 Size Change
@projectwallace/css-parser	47 kB	47.1 kB	+111 B

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commit: 58772c0