Re: [csswg-drafts] [css-anchor-position-1] Clarify how anchor-scope works with display:contents (#12783)

The CSS Working Group just discussed `[css-anchor-position-1] Clarify how anchor-scope works with display:contents`, and agreed to the following:

* `RESOLVED: anchor-scope and similar scoping properties operate on the flattened element tree (not box tree)`

<details><summary>The full IRC log of that discussion</summary>
&lt;ydaniv> TabAtkins: question about how anchor-scope works with display: contents<br>
&lt;ydaniv> ... we can use scope on element and scope to local tree<br>
&lt;ydaniv> ...  question is what happens when on display: contents element<br>
&lt;ydaniv> ... so what exactly is the scope of anchor-scope? flat-tree?<br>
&lt;ydaniv> ... box tree?<br>
&lt;ydaniv> ... I think it should be element relationship tree<br>
&lt;emilio> Tab's suggestion in the issue wfm<br>
&lt;fantasai> +1 to using element tree<br>
&lt;ydaniv> ... otherwise some APIs may break the feature<br>
&lt;flackr> +1<br>
&lt;andruud> FYI: https://github.com/w3c/csswg-drafts/issues/10325<br>
&lt;ydaniv> ... so proposing the flat element tree, not the box tree<br>
&lt;ydaniv> andruud: based on previous discussion in github<br>
&lt;TabAtkins> previous resolution was about flat vs Dom tree<br>
&lt;ydaniv> ... I believe it's on element tree<br>
&lt;vmpstr> q+<br>
&lt;TabAtkins> this is about flat tree vs box tree<br>
&lt;astearns> ack vmpstr<br>
&lt;ydaniv> astearns: proposal is to use the element tree, not box tree<br>
&lt;ydaniv> vmpstr: we have trigger-scope that behaves the same, will this change apply to other properties?<br>
&lt;ydaniv> TabAtkins: yes, should apply to all scoping properties<br>
&lt;fantasai> PROPOSED: anchor-scope and similar scoping properties operate on the flattened element tree (not box treE)<br>
&lt;flackr> +1<br>
&lt;fantasai> RESOLVED: anchor-scope and similar scoping properties operate on the flattened element tree (not box tree)<br>
&lt;ydaniv> astearns: so resolution is that it will affect all scoping proerties<br>
</details>


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Received on Wednesday, 21 January 2026 16:38:11 UTC