I'm sorry, but...
this theme is flawed in two ways:
#1 The white background is no wider than 3750px, so you'll see a grey rectangle expanding from the left hand side (behind your tabs), once your resolution is any higher than that (which is the case when you're using a "4K" UHD display).
#2 There's only one way to tell which tab is currently active and that's by hovering over that tab with your cursor: if it does NOT change in color (ie. you can't select it) it's the active tab.
So if #2 doesn't bother you and you're using a display with a lower resolution than 3750px in width, I guess you're fine, but for me this is unacceptable. I didn't expect it to be this difficult to find a minimalist #fff theme for Firefox.
Rated 1 out of 5 stars by Jens_Jedermann on February 9, 2017
It is good.
Rated 5 out of 5 stars by 机械领主 on March 8, 2016