Add themed scrollbars to the window / overflowing containers

[ndorfin]

Hi @matuzo

One thing that stood out to me, was the default grey scrollbars could do with a lick of paint.

What about re-using the theme colours for the scrollbar track and hold? :)

• Set up scrollbar styling
• Add dark/light-mode theme to scrollbars

-S

[matuzo]

I'm not a big fan of scrollbar styling but if you can make it look nice and maintain usability, go for it! Thanks! :)

[ndorfin]

All good.
I'll try set it up in such a way that it'll be easy to change the colours and thickness of the various scrollbar controls, to help get a look that works.

[ericwbailey]

Sorry for the label spam. I'm doing screen reader lessons with a friend and, well, we wound up in a weird place 😅