Replaces default Firefox black-and-white theme with a more native-looking light/dark compatible translucent theme. If you don't want this much translucent. Check out zvuc's firefox-native-tabbar.
You need to set your theme to "Default" for this tweak to properly work. Works best if you set your system appearance to "Auto" (changing light/dark automatically), then Firefox will follow the OS settings for color scheme.
Please refer to this wonderful guide at userchrome.org for how to set up your own userChrome.css file to enable customizations for the Firefox UI.
Once you have a blank (or existing) userChrome.css file in your Firefox profiles folder, copy-and-paste the code included in the macos-native-tabbar.css file.
Firefox Sliding Bookmarks Bar - Tuck in the bookmarks bar under toolbar to make it slide out only on mouse hover. Makes your firefox cleaner & minimal!
This fork is based on firefox-macos-native-tabbar thanks to zvuc
MIT License