Why Does This Happen? Html Window Width

I am experimenting with html markup and different layouts. I came across this JSFiddle: http://jsfiddle.net/vLJAq/15/ which I played around with and tweaked a little. One thing I d

Solution 1:

The .percent disappears because the width of the window is lower than 400px. The width is calculated by the full actual width of the window less the defined 400px, so the minimum space to show the .percent is 401px.

The .percent shows the width over 400px. If your width of the windows is 410px the .percent has a width of 10px.