Re: [csswg-drafts] [css-align-3][css-position-3][css-anchor-position-1] Allow unsafe endward overflow in scrollable areas? (#12106)

The CSS Working Group just discussed `[css-align-3][css-position-3][css-anchor-position-1] Allow unsafe endward overflow in scrollable areas?`, and agreed to the following:

* `RESOLVED: if your containing block is scrollable, you extend the scrollable area; you don't do alignment safety on the extendable edges of the scrollable area, you let it extend the scrollable area instead`

<details><summary>The full IRC log of that discussion</summary>
&lt;JoshT> fantasai: while working on anchors, we tweaked the rule of abspos boxes alignment so that they stay in their containing block<br>
&lt;JoshT> ... so if alignment causes it to overflow the containing block, we pull it back to the block<br>
&lt;JoshT> ... for scrollable containing blocks, it's not neccessary<br>
&lt;JoshT> ... you can extend the scroll behaviour in the n direction and still honour the author<br>
&lt;JoshT> ... proposing if your containing block is scrollable, you extend the srollable area rather than adjust into the containing block<br>
&lt;JoshT> ... let's say I have something position bottom, if it runs out of the contaning block, it ?????, which authors don't like<br>
&lt;fantasai> s/?????/shifts up to avoid overflowing the CB and consequently covers the anchor/<br>
&lt;JoshT> astearns: TabAtkins said it sounded reasonable<br>
&lt;JoshT> PROPOSED: if your containing block is scrollable, you extend the scrollable area; you don't do alignment safety on the edges of the scrollable area, you let it overflow<br>
&lt;fantasai> +1<br>
&lt;fantasai> s/edges/extendable edges/<br>
&lt;fantasai> s/overflow/extend the scrollable area instead/<br>
&lt;JoshT> RESOLVED: if your containing block is scrollable, you extend the scrollable area; you don't do alignment safety on the extendable edges of the scrollable area, you let it extend the scrollable area instead<br>
</details>


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Received on Wednesday, 15 October 2025 15:50:59 UTC