So much of my experience of browsing the web is fighting sites over how I want them displayed, that I'm beginning to think that I don't want a web browser that renders web pages, and instead I want a web browser that scrapes content from web pages and displays it according to my preferences.
Still working on this. Got as far as the body tag and into the header of the page I'm working on. But, surprise, the HTML is malformed. They failed to close an element. So I had to add a rule so that, if an ancestor element is closed, it treats that as implicitly closing the current element.