Re: [csswg-drafts] [css-forms-1] Further define `::file-selector-button` (#11928)

I've realised even without file-selector-button being element backed there is room for interop issues depending of what we do regarding button layout in base appearance mode.

https://html.spec.whatwg.org/multipage/rendering.html#the-input-element-as-a-file-upload-control - here it says 
> The button is [expected](https://html.spec.whatwg.org/multipage/rendering.html#expected) to use [button layout](https://html.spec.whatwg.org/multipage/rendering.html#button-layout-2) and match the ['::file-selector-button'](https://drafts.csswg.org/css-pseudo/#file-selector-button-pseudo) pseudo-element.

But, button layout actually depends on the type of button: https://html.spec.whatwg.org/multipage/rendering.html#button-layout-2 Firefox uses a real button so it supports a display value of for example inline-flex, but chromium and webkit use input buttons and so won't support this.

This is already observable if you set this display on your `file-selector-button`, if your text is smaller than its container the text alignment is different between a button and input button.

I think we should just specify that this is a real button for the sake of simplicity. It will prevent us having any issues in base appearance.

-- 
GitHub Notification of comment by lukewarlow
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/11928#issuecomment-4239863176 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Monday, 13 April 2026 21:51:41 UTC