I just tried Stylish add-on for Firefox. Works great except I can't seem to figure out a way to make custom styles work for only a specific page. Maybe I'm missing something but there doesn't seem to be a way.
For example if you have .margin-width CSS class defined it will work on any page that has .margin-width CSS class, not just desired page (like Facebook).
For example if you have .margin-width CSS class defined it will work on any page that has .margin-width CSS class, not just desired page (like Facebook).