299995 2025-10-01 17:25:16 -0700 Add align-self/justify-self dialog behavior to enable UA style for popovers 2025-10-15 10:32:10 -0700 1 1 1 Unclassified WebKit CSS WebKit Local Build Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 299630 300817 1 fantasai.bugs fantasai.bugs bfulgham kiet.ho koivisto simon.fraser webkit-bug-importer zalan oldest_to_newest 2147695 0 fantasai.bugs 2025-10-01 17:25:16 -0700 The CSS Working Group recently added a new `dialog` value for align-self/justify-self in order to represent a better default behavior for popovers: centering by default, but using the position-area defaults when anchor-positioned. See https://github.com/w3c/csswg-drafts/issues/10258 This is an issue which trips people up a lot when using anchor positioning combined with popovers, see https://github.com/w3c/csswg-drafts/issues/12466 Opening this bug to track implementation of the new CSS behavior, which is required to update the UA stylesheet per https://github.com/whatwg/html/pull/11656 2147696 1 webkit-bug-importer 2025-10-01 17:25:22 -0700 <rdar://problem/161779751> 2147704 2 fantasai.bugs 2025-10-01 17:30:49 -0700 Pull request: https://github.com/WebKit/WebKit/pull/51658 2147765 3 ews-feeder 2025-10-02 01:30:34 -0700 Committed 300865@main (d7f2e52c03a8): <https://commits.webkit.org/300865@main> Reviewed commits have been landed. Closing PR #51658 and removing active labels. 2151354 4 fantasai.bugs 2025-10-15 10:28:22 -0700 Due to Web-compat, the CSSWG had to change tactics on solving this problem, see https://github.com/w3c/csswg-drafts/issues/10258#issuecomment-3407215102 Consequently, the `dialog` value has been removed from the specs.