See https://wicg.github.io/custom-state-pseudo-class/
<rdar://problem/68320005>
Yes please! Would love to see this in Safari. Would make working with Custom Elements so much better
*** Bug 261726 has been marked as a duplicate of this bug. ***
See https://github.com/whatwg/html/pull/8467 for the latest PR.
*** Bug 264226 has been marked as a duplicate of this bug. ***
A rough draft PR here: https://github.com/WebKit/WebKit/pull/20012
Committed 271600@main (59cb7cb2d924): <https://commits.webkit.org/271600@main> Reviewed commits have been landed. Closing PR #20012 and removing active labels.