Changed to make the buttons follow the theme. The toggle UI button is for temporarily hiding the UI to see the thing obscured by the UI, not to selectively hide unnecessary UI. For that, you could use uBlock Origin. If you mean hiding the buttons of this extension, that would require a separate settings UI, which is a lot of work. Since it currently doesn't have many things, I think I would not add feature to hide buttons for now. Maybe when this extension has more features.