Styling mismatch with Webuniversum

[Windvis]

I noticed that there are some small styling differences between Appuniversum and Webuniversum.

Things I've noticed so for:

• base text color. We don't set it here, so it's the browser default (black, vs dark gray in Webuniversum)
• text selection color. Ours is gray-ish, Webuniversum uses yellow
• input borders + focus styling (+ different variations like error / success)
• button loading colors
• ?

I haven't done a thorough comparison, so there are probably more details we are missing. Ideally we match Webuniversum as good as possible.