This article is to bring light to the !important rule within CSS. CSS by default uses the last specified rule to style a document. However with the use of the !important rule, you can quickly override all subsequent modifications to the same property.
PHP allows you to change the header of a file or page so that it renders differently in the browser. This is VERY powerful if you know how to use it properly.
Based on the PHP headers article, lets write a simple dynamic css file that will change the background to blue if it is monday.