We just recently adopted the search as you type dialog in Wagrail's ReadTheDocs usage.
We've found that the dialog is quite thin on mobile/small devices.

It would be great to have more control over this width or make it something a bit more suitable (responsive). E.g. width: min(95vw, 55rem);.
See our project issue wagtail/sphinx-wagtail-theme#303 (comment)
Possibly related #419 & #292