Fix white CodeMirror-scrollbar-filler on dark themes

[erosman]

Previously #6485

[marijnh]

Won't that still make the element transparent whenever the editor itself is transparent?

[erosman]

Any other ideas?

The white square doesn't look good on dark theme, and even if transparent when editor is transparent, it would still look better than the white square. ;)

What about getting its background-color from the scrollbar background-color?!

[marijnh]

I think adding a rule to color this class in the themes would be the best approach. A bit burdensome, but without using CSS variables (which some of our supported browsers don't have), I don't see a more convenient solution.

[erosman]

That would require the use of var() and @media screen and (prefers-color-scheme: light/dark) which is not supported by older browsers.

Even then, the color will not be a perfect match for all dark themes.

It doesn't bother me as I had already added background-color: inherit; to my own CSS and it works fine for my browser extension use.

I thought the less than ideal inherit might be more adaptable than the status que.