Another way is to just grab any part of the window while pressing the super key. This works in all of the window managers I've used.
Yeah, but for that you need two arms. Sometimes I have a baby in one of them ^^
That makes perfect sense and congratulations! Maybe map some mouse buttons to the same functionality?
If you type "about:profiles" into the URL-bar and create a fresh profile there, does it also happen in that?
(It will practically be like a factory-reset Firefox, except you can go back to your current data/profile.)
Ok, I finally created a new profile and in that profile it's not full width. Now I guess I need to compare the two profiles somehow to figure out what's wrong with mine.
Does right click on the tab bar, click Customize Toolbar, drag the "Flexible Space" where you want it to be work?
I tried to put a flexible space there but it does not work. The flexible space stays very small.
That ain't normal. You can certainly customize Firefox to behave that way with custom userChrome.css file, but you would have to do that on purpose.
I suppose it's also possible that if Firefox is installed via your package manager then they might do some customization to it. I've seen some linux distros package these sorts of custom Firefox builds that apply various changes to official Mozilla builds.
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