Re: [csswg-drafts] [css-forms-1] Should `appearance: base-select` work on listbox selects? (`<select size>`/`<select multiple>`) (#12468)

```html
<style>
select {appearance:base-select; width:0px; padding:0; border:0 }
select::picker(select) { appearance:base-select; display:block }
</style>
<select><option>One</option><option>Two</option></select>
```

This renders the picker element on the page, which acts a little like a list-box. There are some issues, however, as the browser will force the `overlay:auto` property onto the picker when it is open, and there is currently no way for non-UA style sheets to set `overlay:none`. This forces the element to the top-layer on click which is a little jarring, so it would require some more (likely non-trivial) CSS to get it working nicely.

I agree with @josepharhar though - the accessibility tree between `<select>` and `<select multiple>` are considerably different and it might be difficult to rectify this. I suppose if we had the ability to set `overlay:none`, the AT could check if the picker is in the top layer, and if not check if it has layout, and if it does then it is a listbox.

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Received on Wednesday, 16 July 2025 17:06:49 UTC