[microcolonel]

I hate reading on Forbes, it flashes text in the position:fixed headerbar every few seconds, an absolute nightmare to focus on the article while that's happening.(although I do manage to simply remove the headerbar from the page using the dev tools :P)

[dredmorbius]

Install the Stylebot (Chrome) or Stylish (Chrome / Firefox) plugins and make your CSS edits permanent.

I've created over 1000 custom CSS styles over the past 9 months or so fixing various site "errors" such as this. Fixed headers, flyouts, and anything that moves are among the first to go.