[csswg-drafts] [css-value] Clarification on the serialization of the shorthand associated with coordinated value lists (#13500)

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

== [css-value] Clarification on the serialization of the shorthand associated with coordinated value lists ==
How should the shorthand associated with a [coordinated value list](https://drafts.csswg.org/css-values-4/#linked-properties), such as the [`animation`](https://drafts.csswg.org/css-animations/#animation) shorthand property or the [`scroll-timeline`](https://drafts.csswg.org/scroll-animations/#scroll-timeline-shorthand) shorthand property, serialize when the [coordinating list base property](https://drafts.csswg.org/css-values-4/#coordinating-list-base-property) has fewer values than a non base property?

For example, how should the computed style (via getComputedStyle) for `scroll-timeline` serialize when the following properties have been set:

```css
 scroll-timeline-name: '--a, --b;
 scroll-timeline-axis: 'inline, inline, inline;
```

(example comes from https://wpt.fyi/results/scroll-animations/css/scroll-timeline-shorthand.html)

Should it be `--a inline, --b inline`, as the test expects, or `--a inline, --b inline, --a inline` which would be closer to what `animation` and `transition` serializations would do?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13500 using your GitHub account


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Received on Monday, 16 February 2026 02:03:13 UTC