Re: [csswg-drafts] [css-border][css-animation][css-transition] Animations/Transitions of border-width after change of computed value definition in issue #11494 (#13511)

I agree that for https://bug-307933-attachments.webkit.org/attachment.cgi?id=478391, the expected effect after the change to border computed value should be that a solid border pops in at 50% of the way through the transition, then shrinks to 0px over the rest of the duration.

In Chrome Canary I don't see the border animate at all, which seems like a bug. Tagging in @oSamDavis who did the implementation in Chromium.

In Firefox and Nightly I see the border pop in at the start of the transition rather than at 50%, but that's probably a separate issue.

If this is a significant enough web compat issue that we want to address it, I would rather undo the decoupling change with respect to the border properties than special-case border-width to transition off of used values.

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Received on Wednesday, 18 February 2026 01:19:15 UTC