289473 2025-03-10 10:36:23 -0700 Ungraceful degradation for dialog exit animations 2025-03-31 05:51:07 -0700 1 1 1 Unclassified WebKit Layout and Rendering Safari Technology Preview Mac (Apple Silicon) macOS 15 RESOLVED DUPLICATE 276727 InRadar P2 Normal --- 1 jeroen.zwartepoorte webkit-unassigned bfulgham florian graouts ntim simon.fraser webkit-bug-importer zalan oldest_to_newest 2101965 0 jeroen.zwartepoorte 2025-03-10 10:36:23 -0700 https://codepen.io/argyleink/pen/zYbQBOm In STP 214: 1. Click the "Show Dialog" button 2. The dialog and backdrop fadein ✅ 3. Click the "Close" button in the dialog 3.1 The backdrop disappears immediately ✅ 3.2 The dialog moves from the center of the page to near the top of the page ❌ 3.3 The dialog fades out ✅ In Firefox, it degrades gracefully: no movement and no animation. The dialog+backdrop just disappears. I expect STP to *not* do step 3.2. 2101974 1 jeroen.zwartepoorte 2025-03-10 11:06:51 -0700 You can work around the broken exit animation, by doing: ```css @supports not (overlay: auto) { transition-duration: 0s; } ``` Using this, can get WebKit to behave the same as FF on the exit animation. It won't affect Chromium. 2102083 2 webkit-bug-importer 2025-03-10 17:17:27 -0700 <rdar://problem/146701656> 2107384 3 ntim 2025-03-31 05:51:07 -0700 This is because the demo uses the `overlay` CSS property which is not supported by WebKit. *** This bug has been marked as a duplicate of bug 276727 ***