SSIA. It is to update 'fullscreen.css' by adding *|* and also adding namespace and also adding *|* to some WebKit specific rules. Thanks!
Committed 266394@main (3b59a010c260): <https://commits.webkit.org/266394@main> Reviewed commits have been landed. Closing PR #16167 and removing active labels.
<rdar://problem/113046036>