The theme is checked on Ubuntu 20.4 LTS with i3wm

It is a customized version of Firefox i3wm Theme & a bit of code is from Slick-Fox.

• Go to url: about:support

• Under heading Applicaton Basics look for section Profile Directory and click on the Open Directory

• Once in directory look for the folder chrome if there is no such directory, create one, Manually OR Use Terminal:

mkdir -p chrome

• Go to the directory chrome/ and create the file userChrome.css

• Copy and Paste the contents of userChrome.css

• git clone https://github.com/mirbehroznoor/i3wm-firefox-theme

• Paste the userChrome.css file in chrome/ folder

• Go to url about:config

• Search for toolkit.legacyUserProfileCustomizations.stylesheets set it to TRUE

• Restart the Firefox to enjoy your new theme

• Ctrl l or F6 slides down the navigation bar with url selection

There are no one-size-fits-all theme

Have Fun Experimenting