One fine day, i learned about normalize.css, which normalizes all user agents i.e browsers default style to equal. Like there is a difference between padding generated by chrome, IE, Firefox, safari, Opera etc,.
Ever thought how your favorite browser actually works with css and style sheet. If yes, here’s a solution iecss.com have come up with an approach to explain how stuff works. They are giving free resource of different user agent stylesheets like IE 6, IE 7, IE 8, IE9, Firefox 3.6.3, Webkit (r57042), opera 10.51.