some changes I did to CSS part

1. I think it's better we can unify the indentation to 4 spaces (though I did not change it, I want to know your opinion)
2. I fixed some mistakes in your sample code
3. I updated the clear fix part

* Please review the js part, and leave your comments, I did not put in jQuery plugins & Dojo widget, because after some thoughts, I think those should not be in the standard, it's something you need to learn from their official site. Do you agree?