Percentage dimensions of the left menu layout

All the dimensions are in percentage widths so the layout adjusts to any screen resolution. Vertical dimensions are not set so they stretch to the height of the content.

Maximum column content widths

To prevent wide content (like long URLs) from destroying the layout (long content can make the page scroll horizontally) the column content divs are set to overflow:hidden. This chops off any content that is wider than the div. Because of this, it's important to know the maximum widths allowable at common screen resolutions. For example, if you choose 800 x 600 pixels as your minimum compatible resolution what is the widest image that can be safely added to each column before it gets chopped off? Here are the figures:

800 x 600
Left column: 162 pixels
Main page: 550 pixels
1024 x 768
Left column: 210 pixels
Main page: 709 pixels

The nested div structure

I've colour coded each div so it's easy to see:

The header, colmask and footer divs are 100% wide and stacked vertically one after the other. Colleft is inside colmask. The two column content divs (col1 & col2) are inside colleft. Notice that the main content column (col1) comes before the side column.

No CSS hacks

The CSS used for this layout is 100% valid and hack free. To overcome Internet Explorer's broken box model, no horizontal padding or margins are used. Instead, this design uses percentage widths and clever relative positioning.

SEO friendly 2-1 column ordering

Centered menus compatible

This layout is fully compatible with my cross-browser compatible centered menus.