title: Add CSS to pages through a CSS file
body: <p>I was wondering if it was possible to add CSS to pages through a CSS file, similarly to adding JS to pages through a JS file (contentscript). So, I could just define what pages said CSS file would work on and then it would take effect just like a contentscript. I understand that it is possible to add CSS through a JavaScript file, but it would be more convenient to do it this way instead if possible. If it's not possible, then of course I must use contentscript, but I would first like to know before I rule out any possibilities. I've searched and received no answers - either I'm searching wrong or it really isn't possible. Chrome extensions have come a long way, though, so I'm still not ruling it out until someone who knows can tell me yes &amp; how or no. Thanks for any responses.</p>