Kill the old-style CSS box model with 'box-sizing: border-box '

* {-moz-box-sizing: border-box;
-webkit-box-sizing: border-box; 
box-sizing: border-box;}

This small piece of code re-works the default CSS box model by forcing the web browser to use any extra border and padding attributes and include them in the set-width of an object rather than add it.

For example, a 200px box with 10px padding and a 5px border would still be viewed as 200px wide and NOT the standard width of 230px (200 + 10 + 10 + 5 + 5).

It's pretty awesome but remember, it doesn't work for margins (shame).