finally perfect dark theme

Description checked out 😄 perfect contrast / text dimming (other themes are too much or too little), and that annoying white outline between web contents and FF UI is gone. Only improvement needed is active tab highlighting, but i think itll grow on me.

Perfect! Would've liked the Firefox homescreen to be darker though, but that's not a big deal.

Perfect dark theme - thanks a lot!

Very good, uniform, no light lines between tabs and address bar. clean and smooth, i like much!