Dark theme: Safari: styling of version switcher in narrow window

[m-aciek]

I am not sure even if it's worth fixing, but just wanted to drop the note, that on Safari 16.3 (18614.4.6.1.6) selector for version is not being styled as "quick search" box. It used to be of the same style before the update (https://github.com/python/python-docs-theme/pull/44).

3.11:

cc @septatrix

[septatrix]

Sadly I do not have access to a Safari browser and cannot reproduce this on Chrome or Firefox. I see that the wrapping element span.version_switcher_placeholder was previously a div and that it previously had appearance: none; set which was cumbersome with the dark styles because it requires many more manual overrides. If with Safari someone wants to investigate, this might be some starting points.

[hugovk]

I can reproduce (Safari 16.3/macOS Ventura 13.2.1), but also note they're the same for wider window:

It would be nice to fix this, and have them consistent like this for both layouts (and possibly the theme and language selectors too):

But I don't think this is a showstopper to go live with the dark theme.