This is a custom interface which puts everything on the navbar in one line via userChrome.css and also adds a black background to the homepage and the settings pages via userContent.css I've also added BetterFox's user.js in this with a couple of overrides which I like.
HOW TO INSTALL:
Download and unzip (from Repo or from Releases)
Go to about:profiles in Firefox and open your Profile Folder by selecting root directory
Drop the user.js in the root folder
Drop your unzipped "chrome" folder in the root folder
Go to about:config in your Firefox and set the value of toolkit.legacyUserProfileCustomizations.stylesheets to true (this enables the loading of userChrome mods)
Restart Firefox
Additional Tips:
Hamburger icon > More Tools > Customize Toolbar -> Disable Title Bar (Mac and Linux Users)
Hamburger icon > More Tools > Customize Toolbar -> Switch to Compact for Toolbar (Multiplatform)
GALLERY:
CREDITS:
userChrome.css: https://github.com/Bali10050/FirefoxCSS