The magic numbers
62.5%
in CSS setting the font-size on the body tag to 62.5% gives you a base unit of ten pixels so to set type to 12 pixels high specify 120% and so on. Using percentage fonts allows the designer to set well balanced type while letting the user have control over the size.
960
The average web page width, gives decent guttering either side of centred content on a 1024 screen. Also allows beautiful grid based designs using 12 columns with 10px guttering either side, see http://960.gs/ for more on grid systems
600
A reasonable approximation of the much over emphasised fold, the initial viewable area of a web page on the ’standard’ screen size of 1024×768. Different browsers come equipped with a bunch of features that take up space around the actual page contents. To allow for this negative space across the major browsers a page depth of 600 pixels fits like a glove.
1.6180339887 - The Mighty Phi
In mathematics and the arts, two quantities are in the golden ratio if the ratio between the sum of those quantities and the larger one is the same as the ratio between the larger one and the smaller. The golden ratio is approximately 1.6180339887.
