[dns_snek]

I use this method personally and it works great on GNOME and KDE. First set `toolkit.legacyUserProfileCustomizations.stylesheets` to true in `about:config` then find your profile directory in `about:profiles`.

    cd $FIREFOX_PROFILE_DIR
    cd chrome
    git clone https://github.com/MrOtherGuy/firefox-csshacks
    touch userChrome.css

The contents of userChrome.css should be:

    @import url('firefox-csshacks/chrome/hide_tabs_toolbar.css');
    @import url('firefox-csshacks/chrome/window_control_placeholder_support.css');

Then restart the browser. If anything breaks the repository will likely be updated soon and you just have to pull the changes.