TIL protonmail lets you use custom css (haven't played with it tho)
@emsenn You can use custom css for FireFox too.
@johny I've heard! I've only just learned to do any CSS, so am not keen on messing with any websites, but it's always cool to see software service providers that offer it built-in.
@emsenn If you are using windows there is bug on installation, but its reported on github.