refresh css need to use crtl-f5

http://stackoverflow.com/questions/385367/what-requests-do-browsers-f5-and-ctrl-f5-refreshes-generate

Generally speaking:

F5 may give you the same page even if the content is changed, because it may load the page from cache. But Ctrl-F5 forces a cache refresh, and will guarantee that if the content is changed, you will get the new content.