来自http://tunps.com/mainstream-browser-buildin-css
The UA Style Sheet is a simple set of css styles that each web browser uses before any other css styles are applied.
This chart lists and compares the different default style sheets used to render HTML in the four major versions of Internet Explorer; IE6, IE7, IE8, and IE9 Platform Preview.
You can download each of these UA stylesheets by using the links at the top of this chart.
