Originally Posted by Lord Kalthorn Ok, I managed to fix it. What I apparently did not realise was that for some strange I frankly stupid reason Firefox widths are content widths, not actual widths. They do not seem to include margins or padding!

that's how CSS works. go through w3.org and see for yourself.

and the point is to be logical. width: 100%; padding:10px;
you first tell it to make a box 100% of the browser window, so it does. the next instruction is to add 10px to the top,right,bottom,left of said box.