The https://drafts.csswg.org/css-scrollbars-1/#scrollbar-width definition for the 'thin' value already explicitly asks for the requested behavior: "remain wide enough to be usable" and cites WCAG accordingly. If folks have suggestions for better / stronger language or citations that we could use, please feel free to file an issue on the Scrollbars Styling draft at https://github.com/w3c/csswg-drafts/labels/css-scrollbars-1 with suggestions! Thanks, Tantek (Scrollbars Styling co-editor)

The https://drafts.csswg.org/css-scrollbars-1/#scrollbar-width definition for the 'thin' value already explicitly asks for the requested behavior: "remain wide enough to be usable" and cites WCAG accordingly.

If folks have suggestions for better / stronger language or citations that we could use, please feel free to file an issue on the Scrollbars Styling draft at https://github.com/w3c/csswg-drafts/labels/css-scrollbars-1 with suggestions!

Thanks,

Tantek (Scrollbars Styling co-editor)