I found this[0] minimal style (not by me) particularly useful, with auto-folding and a thin visual footprint. [0] https://github.com/ongots/firefox-sidebery-mi

I found this[0] minimal style (not by me) particularly useful, with auto-folding and a thin visual footprint. [0] https://github.com/ongots/firefox-sidebery-minimal-style https://github.com/ongots/firefox-sidebery-minimal-style (screenshots further down the page)