[csswg-drafts] [css-nesting-1][css-cascade-6] Conflicting definitions of nested/scoped style rules and the nesting selector (#13517)

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

== [css-nesting-1][css-cascade-6] Conflicting definitions of nested/scoped style rules and the nesting selector ==
[CSS Nesting](https://drafts.csswg.org/css-nesting-1/#conditionals) states the following about the contents of nested group rules:

  > - Style rules are nested style rules, with their nesting selector taking its definition from the nearest ancestor style rule.

But [CSS Cascade 6](https://drafts.csswg.org/css-cascade-6/#scope-effects) states that style rules in `@scope` are scoped style rules, with their nesting selector taking its definition from it:

  > - The style rules in an `@scope` `<rule-list>` are scoped style rules.
  > - The `&` selector is defined to behave as `:where(:scope)`.

I think that *nested style rule* and *scoped style rule* are exclusive, since a scoped style rule may not have an ancestor style rule.

I think it may be appropriate to append *"unless the nested group rule is `@scope`, in which case it is a [scoped style rule](https://drafts.csswg.org/css-cascade-6/#scoped-style-rules)"*, in the CSS Nesting definition.

[CSS Nesting](https://drafts.csswg.org/css-nesting-1/#nesting-at-scope) also states:

  > When the `@scope` rule is a nested group rule, an `&` in the `<scope-start>` selector refers to the elements matched by the nearest ancestor style rule.

While [CSS Cascade 6](https://drafts.csswg.org/css-cascade-6/#scope-limits) states:

  > Any `:scope` or `&` selectors in `<scope-start>` are interpreted as defined for its outer context.

And if the closest outer context is `@scope`, then it is defined by CSS Cascade 6 as `:where(:scope)` (see the first quote above), instead of _the elements matched by the nearest ancestor style rule_.

I think it may be appropriate to append *"unless there is a closer `@scope`, in which case it behaves like `:where(:scope)`"*, in the CSS Nesting definition, as stated in its non-normative note.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13517 using your GitHub account


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Received on Wednesday, 18 February 2026 17:34:14 UTC