Ergodark од Götz Kluge

Recommended by Mozilla from mid December 2020 to mid February 2021.

At work I use this dark, eye friendly, and non-distracting theme for the Firefox browser. The theme might even be a bit boring, but that's what I need if the work is not boring.

The window control symbols in the upper right corner can be either black (e.g for my Linux computers) or white (e.g. for my Windows computers).

2021-06-08: Update of "Ergodark" due to FF's introduction of Proton.
I use "Ergodark 2" and sometimes "Dark Snark 2", both with a green active tab border.