How to change firefox default tab size and fix wonky tab behavior

Under your profile folder create a chrome/ folder

cd /home/`whoami`/.mozilla/firefox/*default*
mkdir chrome
cd chrome

Create userChrome.css file

touch userChrome.css

Update userChrome.css with the following lines:

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
.tabbrowser-tab:not([pinned]) {
max-width: 80px !important;
}
.tabbrowser-tab:not([pinned]):not([fadein]) {
max-width: 0.1px !important;
}

 

Restart firefox and enjoy

Source:
https://www.askvg.com/how-to-customize-and-change-width-or-length-of-tabs-in-mozilla-firefox/Read the rest