232402 2021-10-27 14:04:23 -0700 :empty selector matches elements with a shadow root 2021-10-29 12:19:20 -0700 1 1 1 Unclassified WebKit CSS Safari 15 Unspecified Unspecified RESOLVED INVALID P2 Normal --- 1 lwarlow webkit-unassigned emilio oldest_to_newest 1809417 0 lwarlow 2021-10-27 14:04:23 -0700 Steps to reproduce: Go to https://jsfiddle.net/hyjfkwqx/ You should see there is no output. Actual results: The :empty selector matches an element with an open shadow root that itself has child elements. So the parent div is not displayed. Expected results: I would expect the :empty selector to not match these elements. So I would expect to see a red square with a smaller blue square in it. 1809420 1 lwarlow 2021-10-27 14:05:04 -0700 Chrome Bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1264139 Firefox Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1738113 1810070 2 lwarlow 2021-10-29 08:27:36 -0700 I made an issue in the CSSWG github just in case it's a spec "issue" rather than a browser one. https://github.com/w3c/csswg-drafts/issues/6771 1810184 3 emilio 2021-10-29 12:19:20 -0700 Let's reopen if the CSSWG decides to change behavior here but this is invalid as per spec.