Created attachment 314000 [details] Correct behaviour in MacOS Steps to reproduce the problem: Over-sized elements calculate percentages based on when overflow is applied. See https://codepen.io/cliener/pen/PjjJYM?editors=1100#0 What is the expected behavior? Percentage widths should be calculated on the width of the parent instead of the element itself. For example, if the window width is 1000px and the over-sized element 1400px, setting width of 50% on the over-sized element should set the width to 500px. What went wrong? Widths are calculated on the width of the element not of the parent. Following the example above, if the window width is 1000px and the over-sized element 1400px, setting width of 50% on the over-sized element sets the width to 700px. Did this work before? Safari 10.1.1 MacOS calculates the value correctly. Safari in iOS 10.3.2 does not. Unsure about earlier versions.
Does this reproduce in a recent Safari Tech Preview?
(In reply to Simon Fraser (smfr) from comment #1) > Does this reproduce in a recent Safari Tech Preview? Not relevant to tech previews since it only occurs in iOS. Haven't tested in iOS 11 beta(s)
I am not able to reproduce this in iOS 16.0.2 on iPhone 13 Pro Max using below CodePen from Comment 0 and it behave similar to desktop and does not have any overflow issue. Marking this as "RESOLVED CONFIGURATION CHANGED". Please reopen with updated testcase, if this is reproducible. Thanks!