Made to be used with TreeStyleTabs.
Save the file in the 'chrome' folder located in your Firefox's profile directory. If the folder doesn't exist, create it.
To get to your to your Firefox profile directory, either navigate to about:profiles in a new tab and open the root directory, or go there manually:
- Linux: /home/<username>/.mozilla/firefox/xxxxxxxx.default
- Windows: C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxxxx.default
- Mac: Users/<username>/Library/Application Support/Firefox/Profiles/xxxxxxxx.default
Once you're done, the file's full path should look something like this:
- /home/<username>/.mozilla/firefox/xxxxxxxx.default/chrome/userChrome.css