<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <style type="text/css"> div { width:100px; height:100px;position:absolute; top:10px; filter: Alpha(Opacity=50); /* 针对IE*/ background-color: rgba(0, 0, 0, 0.5); /*针对其他浏览器*/ } </style> </head> <body> <h1>hello</h1> <div></div> </body> </html>
div块覆盖在hello上，依然是透明的
原文：http://www.cnblogs.com/jason-gong/p/3719423.html