http://www.quirksmode.org/bugreports/archives/safari/index.html "Safari will omit the right padding of an element in a floated container if that element has trailing whitespace. Workaround is to ensure any elements with padding have no whitespace before the closing tag. (ppknote: The test page is a mess in IE Mac, but the bug is not the same) Test page http://moshpit.org/quirksmode/safari_float.html Workaround is included Reported by: Alan Harder."
Changing component, confirming the bug.
Created attachment 26298 [details] test case
Created attachment 461142 [details] Safari 15.6 matches Chrome but differs from Firefox I am not clear on expected result but based on rendering output Safari 15.6 on macOS 12.5 based on test case matches with Chrome Canary 105 but differs from Firefox Nightly 104 as can be seen from attached screenshot. Appreciate if someone else can share more input on what direction should Webkit take here. Thanks!
<rdar://problem/97457285>
Even though the rendering differs between WebKit/Blink and Gecko, the original bug being reported has been fixed -> Config Changed.