113519 2013-03-28 10:49:19 -0700 for flex items, percent margins and paddings should resolve against their respective dimension 2018-02-09 14:51:07 -0800 1 1 1 Unclassified WebKit Layout and Rendering 528+ (Nightly build) Unspecified Unspecified NEW P2 Normal --- 1 tony webkit-unassigned cbiesinger claude.pache dholbert m.goleb+bugzilla webkit oldest_to_newest 865625 0 tony 2013-03-28 10:49:19 -0700 Normally, margin top and margin bottom resolve against the width of the containing block, but the working group decided that for flex items, we should resolve against the height of the containing block. http://lists.w3.org/Archives/Public/www-style/2013Mar/0688.html This should be an easy change to make. See RenderFlexibleBox::computeChildMarginValue. 920002 1 cbiesinger 2013-08-22 16:03:16 -0700 *** Bug 120003 has been marked as a duplicate of this bug. *** 969294 2 dholbert 2014-01-17 15:45:58 -0800 *** Bug 126809 has been marked as a duplicate of this bug. *** 1398088 3 m.goleb+bugzilla 2018-02-09 14:23:39 -0800 Both Edge & Firefox teams have committed to change to align with the Chrome/Safari behavior. The spec also got an update to mandate this behavior: https://drafts.csswg.org/css-grid-1/#item-margins It sounds that this issue should be closed as "Won't Fix". 1398097 4 dholbert 2018-02-09 14:51:07 -0800 Right -- and the spec changed, too, such that WebKit is now correct according to the spec. So really this could now be "Resolved|Invalid", in the sense that WebKit is matching what the spec requires, i.e. the reported behavior is actually correct/intentional & not a bug. (At least, that'd be the correct resolution if this were in the Mozilla/Firefox bug tracker -- I'm not sure if the bug-resolution semantics are the same in WebKit's bug tracker.)