- From: Guillaume via GitHub <noreply@w3.org>
- Date: Thu, 19 Mar 2026 12:57:55 +0000
- To: public-css-archive@w3.org
cdoublev has just created a new issue for https://github.com/w3c/csswg-drafts: == [css-masking-1] Disallow negative values in `mask-border` longhands == This would make them match the [`border-image`](https://drafts.csswg.org/css-backgrounds-3/#border-image) longhands. I think the reasoning for disallowing them in `border-image` longhands should probably also apply to `mask-border` longhands. Namely, for [`mask-border-slice`](https://drafts.csswg.org/css-masking-1/#the-mask-border-slice), [`mask-border-width`](https://drafts.csswg.org/css-masking-1/#the-mask-border-width), since this is already specified in prose for [`mask-border-outset`](https://drafts.csswg.org/css-masking-1/#the-mask-border-outset): > Negative values are not allowed for any of the `mask-border-outset` values. Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13682 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Thursday, 19 March 2026 12:57:56 UTC