[css-houdini-drafts] [css-properties-values-api-1] Should `@property` always be invalid with CSS-wide keywords or property substitutions for `initial-value`? (#1130)

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

== [css-properties-values-api-1] Should `@property` always be invalid with CSS-wide keywords or property substitutions for `initial-value`? ==
There is this note about [computationally independent](https://drafts.css-houdini.org/css-properties-values-api-1/#computationally-independent) values:

  > [...] `3em` is not computationally independent [...]. **Neither is a value with a `var()` function**, because it relies on the value of a custom property.

Browsers make `@property` invalid with `syntax: "<custom-ident>"` and `initial-value: initial` ([WPT](https://github.com/web-platform-tests/wpt/blob/72b510aca3019a3f56bc62cfa6b25484ad2231b6/css/css-properties-values-api/register-property-syntax-parsing.html#L232)) whereas `initial` is computationally independent. If `initial` cannot match `<custom-ident>`, neither can `var(--custom)`. Both are valid property values, no matter the property value definition.

Similarly, `syntax: "<length>"` with `initial-value: first-valid(1vmin, 20px)` seems reasonable. But that might also not be allowed (cf. [#1120](https://github.com/w3c/css-houdini-drafts/issues/1120#issuecomment-2398936210)).

Please view or discuss this issue at https://github.com/w3c/css-houdini-drafts/issues/1130 using your GitHub account


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Received on Tuesday, 8 October 2024 06:19:21 UTC