title: Is there a way to automatically make CSS/HTML changes to a web page each time it is loaded?
body: <p>I sometimes use Firebug to fix problems with webpages or to hide certain things. I am simply a user of these webpages and cannot change the source. I would like to be able to automate this so that each time I visit a website, certain modifications are performed. Right now, I need to redo the same edits each time the page is loaded.</p>
  
  <p>I am open to using other tools than Firebug, since I'm not sure it is capable of doing this.</p>