Created attachment 462083 [details] HTML file showcasing the issue Compare the attached HTML file in different browsers. Safari is the only one that renders the red square over the black border.
<rdar://problem/99475341>
Created attachment 462087 [details] rendering in Safari, Safari TP, firefox, chrome Tested on macOS 13.0 --- Safari 16.1 18614.2.1.1.1 Safari Technology Preview 16.0 18615.1.2.3 Firefox Nightly 106.0a1 10622.8.31 Google Chrome Canary 107.0.5275.0 5275.0 the div doesn't have a 1:1 ratio but a 1:2 ratio.