the layout and the font appearance heavily differed on different browsers and was depending on font size presets. Most notably NatSkin was unusable with firefox using an average font size of 12pt. While 16pt was ok for NatSkin, konqueror was nearly the same using 12pt. So now font sizes are not relative to browser presets anymore (using small, x-small, normal, large, x-large and the like) but initializes fonts to a pixel value and uses relative values (% or em) to get different font sizes.