I just noticed that mastodon (or fosstodon, never tried other instances) managed to customize the scroll on firefox. Didn't know that was possible, I've tried a lot of times but never succeeded :(
@SonoMichele You mean like being able to have multiple scroll bars in your page, one per column? If that's what you're looking for, IIRC it's a standard CSS feature "overflow". https://developer.mozilla.org/en-US/docs/Web/CSS/overflow
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.