This exactly what I was looking for. Simple and no useless stuff. Nice addon.

Btw, Can you add an option to increase the font size and another keybinding Ctrl + E (unused) for toggling the tab bar?

Please help, is there a way to modify the sidebar.css? what can I specify in my userChrome.css to change the --sidebar-bg-color and --tab-bg-color

Simple, minimalistic. Great if there was an option to adjust density and font size. Other than this, fantastic