[csswg-drafts] [css-mixin-1] How does Shadow DOM influence mixin lookup? (#12671)

sesse has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-mixin-1] How does Shadow DOM influence mixin lookup? ==
Similar to #12670, we are supposed to only see previously defined mixins. But Shadow DOM makes “order” more complicated. Which rules from the parent tree scope should an `@apply` in Shadow DOM see? Should it be all of them? Or just the ones defined before shadow host's position in the light DOM? Or perhaps order should be counted by the flat tree? (This can be pretty interesting if we start getting slotted children with <style> nodes in them.)

Similarly, what can adopted style sheets see? Can they provide mixins? If an adopted style sheet with an `@apply` is used in both the parent and the shadow, does that mean it can see different mixins in each?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/12671 using your GitHub account


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Received on Thursday, 28 August 2025 10:39:48 UTC