This is, of course, an exaggeration of the both of them. Each has its own use case in which it performs better than the alternative. In truth, I use ubo as much as I use reader view :)
@-moz-document url-prefix("about:reader") {background-color: #000000;} in your usercontent.css
Thanks, I only had to add !important and it changed the background.
@-moz-document url-prefix("about:reader") {background-color: #000000;} in your usercontent.css
Thanks, I only had to add !important and it changed the background.