303059 2025-11-24 10:46:26 -0800 Default value of custom property not recognizing by CSS Style Container Query with certain formatting 2026-05-27 04:36:16 -0700 1 1 1 Unclassified WebKit CSS Safari Technology Preview Mac (Apple Silicon) iOS 26 RESOLVED FIXED https://github.com/web-platform-tests/wpt/pull/60208 https://jsfiddle.net/g04yvhp8/ InRadar P2 Normal --- 1 imbashenk ahmad.saleem792 ahmad.saleem792 koivisto sam simon.fraser webkit-bug-importer oldest_to_newest 2161095 0 imbashenk 2025-11-24 10:46:26 -0800 When using a custom property with a default value it is not recognized in a style container query, when it is formatted with e.g. prettier. This does work in Chrome. In short: ``` html { /* valid */ --my-container-var: var(--my-undefined-var, "my-default-value"); /* invalid */ --my-container-var: var( --my-undefined-var, "my-default-value" ); } body { @container style(--my-container-var: "my-default-value") { --my-font: "Helvetica Neue", Helvetica, Arial, sans-serif; } } p { font-family: var(--my-font); } ``` 2162226 1 webkit-bug-importer 2025-12-01 10:06:29 -0800 <rdar://problem/165627262> 2213794 2 ahmad.saleem792 2026-05-25 02:11:05 -0700 Pull request: https://github.com/WebKit/WebKit/pull/65609 2214900 3 ews-feeder 2026-05-27 03:57:48 -0700 Committed 313957@main (2f8d1192d466): <https://commits.webkit.org/313957@main> Reviewed commits have been landed. Closing PR #65609 and removing active labels.