I think I might be missing something here. I'm trying to create a liquid layout as described in this months .Net magazine, which mainly uses .em sizes for accessibility as opposed to a pixel-perfect layout. The main issue I have is that when adding borders, padding and margins the resulting sizes of div sections are different between IE6/7 and Firefox. IE still seems to include the borders, margins and any padding inside the specified width of the box, whereas Firefox (correctly, AFAIK) takes the specified width + margins + padding + borders to calculate the final width of the area. I thought that this "bug" was only supposed to affect IE5/.5 and early Opera browsers, but was rectified for IE6 and 7. As far as I have experienced, this is not the case. Where am I going wrong? Edit: Also, I've tried using the box model hack which was designed for IE5/.5 but this hasn't solved the problem.