303703 2025-12-07 01:07:16 -0800 Container style queries stop applying after user interaction when ancestor uses display: contents and defines the queried custom property 2025-12-07 03:58:38 -0800 1 1 1 Unclassified WebKit CSS Safari 26 Unspecified Unspecified RESOLVED DUPLICATE 301871 P2 Major --- 1 kobiz webkit-unassigned koivisto moiseev.andy oldest_to_newest 2163950 0 kobiz 2025-12-07 01:07:16 -0800 When using a CSS container style query that depends on a custom property defined on an ancestor with display: contents, the styles inside the @container block initially apply correctly on load. After a simple user interaction (clicking the button), the styles inside the container style query stop applying. This reproduces in Safari on iOS and Chrome on iOS (WebKit-based), but not in Chrome on desktop or Android (Blink). This looks like a WebKit bug related to invalidation / reevaluation of container style queries when the container ancestor uses display: contents. Steps to Reproduce: ``` <!doctype html> <html> <head> <meta charset="utf-8" /> <title>WebKit container style query + display: contents bug</title> <style> .preset-wrapper { display: contents; --preset: pink; /* In real code this element is a style container. Even in this simplified example, WebKit initially applies the style query correctly. */ } .button { position: relative; width: 200px; height: 80px; } @container style(--preset: pink) { .button { background: pink; color: black; } } </style> </head> <body> <div class="preset-wrapper"> <button class="button" id="btn-1">Hello</button> </div> </body> </html> ``` 1. Open the page in Safari 2. Observe the initial button style when the page loads. 3. Tap / click the button once. Actual Results: On initial load: The rules inside @container style(--preset: pink) are applied. After clicking the button: The rules inside the container style query are no longer applied. Expected Results: The container style query @container style(--preset: pink) should continue to apply as long as the custom property --preset: pink remains in effect on the container ancestor. A simple user interaction (click/focus/active state on a descendant button) should not cause container style queries to stop applying. 2163954 1 kobiz 2025-12-07 03:58:38 -0800 *** This bug has been marked as a duplicate of bug 301871 ***