[csswg-drafts] [css-transitions-2] Explicitly define what is valid/invalid in `@starting-style` (#9151)

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

== [css-transitions-2] Explicitly define what is valid/invalid in `@starting-style` ==
The spec does not explicitly define what is valid/invalid in its block value, as required by [CSS Syntax](https://drafts.csswg.org/css-syntax-3/#block-contents), and I guess this list below is not exhaustive:

  > Global, name-defining at-rules such as `@keyframes`, `@font-face`, and `@layer` are allowed inside `@starting-style` [...]

However I wonder if `@starting-style`, `@namespaces`, `@import`, are allowed.

As noted in #9114, rule definition tables may be more appropriate, but a basic syntax (`@starting-style { <rule-list> }`) would still help `w3c/reffy` to extract a definition of `@starting-style`.

---

*Asides*

  > The `@starting-style` rule is a grouping rule.

A *nested group rule* is any at-rule whose block value can contain a style rule.

A *conditional group rule* can contain style rules.

But the meaning of a *grouping rule* is unclear to me. Are *grouping rule* and *grouped style rule* (cf. below) different? Can you please define these terms?

  > The rules inside `@starting-style` cascade as any other grouped style rules without introducing any new ordering to the cascade, which means rules inside `@starting-style` do not necessarily win over those outside.

Defining a rule as cascading is confusing to me. Does it mean that *declarations in style rules nested in `@starting-style` cascade as any other style rules outside of `@starting-style`*?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/9151 using your GitHub account


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Received on Thursday, 3 August 2023 09:24:05 UTC