Starting March 31, 50% of Firefox beta 138 users will have the change where <h1> always has the same UA style, even in article, aside, nav, section.
Also, Lighthouse will fail a check if you have an <h1> 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