Suggestion: create a more KDE compliant variant.

[ripefig]

The current theme isn't consistent with Arc-KDE. I am thinking that it would be a good idea to make a more KDE friendly variant as a supplement.

Here's a a preview of Arc-KDE on my system (I've tweaked the color of the pressed buttons to make them less jarring):

A few minor tweaks would make for a very good cross-platform theme:

1. Change the sidebar color in the file manager and picker to a normal light grey color. The current black sidebar looks bad on KDE.

2. Ensure that the toolbars and headerbars are able to merge with the server-side decoration. This means toolbars and headerbars should have the same style. (I've tweaked the CSS on my system to eliminate the curvature of the headerbar). This is important because people on KDE generally force server-side decorations for CSD apps.

3. The blue toolbar and headerbar buttons look distracting and out of place on KDE. I'd propose making them grey.

If you don't want to do it, I'll try doing it myself. But I am not sure the changes I make will be well-written enough to be upstreamed.

[NicoHood]

Feel free to open a PR to fix the issues.