Exactly screen-centered div, pure CSS. Requires no knowledge of div size or setting any CSS attributes outside of the centering frame. Requires only five attributes. Works in all major browsers.
other example
http://css-tricks.com/snippets/css/keyframe-animation-syntax/
https://dhirajkumarsingh.wordpress.com/2013/01/01/css3-3d-effect-shine-text-with-css3-keyframe-animation-scrolling-page-background-with-jquery-happy-new-year/