http://hail2u.net/blog/webdesign/opacity-and-z-index.html
Sun Feb 05 2012 13:21:36 GMT+0900 (JST)
opacityとz-indexプロパティーの組み合わせには近寄らない方が良さそう
http://frog-on-air.blogspot.com/2012/02/actionbardrop-down.html
Sun Feb 05 2012 13:18:20 GMT+0900 (JST)
http://jsdo.it/hondam/7woV
Sun Feb 05 2012 13:17:37 GMT+0900 (JST)
css3
http://coliss.com/articles/build-websites/operation/css/css3-tutorial-animated-tooltips-by-codrops.html
Sun Feb 05 2012 13:17:10 GMT+0900 (JST)
http://d.hatena.ne.jp/minghai/20120203/p1
Sun Feb 05 2012 13:16:04 GMT+0900 (JST)