*{padding:0;margin:0;}
.ab{ width:100%; background-color:#eee; height:250px; text-align:center; line-height:250px;}
.bc{ width:100%; background-color:#eee; text-align:center; text-align:center; color:#fff; font-size:24px; background-color:#060;}
.pf{ width:100%; height:50px; background-color:#C00; text-align:center; line-height:50px; color:#fff;}
html{ _background-image:url(about:blank); _background-attachment:fixed;}
.float{ position:fixed; z-index:999999; top:0px;}
* html .float{ position:absolute; _top:expression(documentElement.scrollTop-0);}
第一版块
漂浮内容
