Firefox Quantum made it so that extensions can't hide the tabs on top. It can only be done manually, by making and editing a userChrome.css file. https://super

Firefox Quantum made it so that extensions can't hide the tabs on top. It can only be done manually, by making and editing a userChrome.css file. https://superuser.com/questions/1268732/how-to-hide-tab-bar-tabstrip-in-firefox-57-quantum https://superuser.com/questions/1268732/how-to-hide-tab-bar-...