I don't know anything about scripting and this will be the first time that I ever tried to create a Greasemonkey script. I couldn't find an existing Mozilla Firefox add-on or user script, so that is why I had to resort to such measures.
So anyway, there is a website that I visit on a regular basis. Let's call it http://www.DARNSITE.com. It has been adding an additional, unnecessary, and non-functional vertical scrollbar next to the browser's vertical scrollbar.
I want to create a user script that changes this line:
<main class="bucket__main" style="overflow:hidden;">
This should do the trick if there is only one occurence of the class bucket__main: