Starting March 31, 50% of Firefox beta 138 users will have the change where

always has the same UA style, even in article, aside, nav, section.

Also, Lighthouse will fail a check if you have an

without font-size specified.

Advice for web developers: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/Heading_Elements#specifying_a_uniform_font_size_for_h1

Context: https://mastodon.social/@zcorpan/113839012551439287

Here's the new 2025 reset.css:

h1 { margin-block: 0.67em; font-size: 2em; }

Thank you for adopting this on all your sites!

See https://github.com/whatwg/html/issues/7867