This piece from @heydon details his system for using the new features of #CSS to test HTML for proper semantics and structure. Just incredible what’s going on in some of these selectors.
https://heydonworks.com/article/testing-html-with-modern-css/
Testing HTML With Modern CSS
CSS can be a great HTML testing tool, especially in 2024Heydon Pickering (heydonworks.com)