My Firefox updated automatically yesterday. Holy crap this looks terrible. In the last version, I could set it so floating tabs didn't happen - and things looked vaguely normal - by changing a setting in about:config.
Apparently the ability to change that setting was a "feature", that was only for "testing" and has been removed (I believe there was Proton and Photon, and Proton was the one I was able to deactivate successfully, mostly returning things to normal).
Anyone found a fix to try and make it look, well, good again? The Bookmarks menu stretches way out past the end of the screen now, before all this was nicely compacted into one dropdown menu.
Some Firefox forums mention something called css.chrome but I don't know much about it.
https://support.mozilla.org/en-US/questions/1346781
https://support.mozilla.org/en-US/questions/1346582
I did find this but it looks a bit full-on for me...