<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>CSS3:透明度</title>
<style type="text/css">
div{
width:100px;
height:100px;
margin: 40px;
display: inline-block;
background-color: #ee3e80;}
p{
width: 100px;
height: 100px;
position: relative;
top: 20px;
left: 20px;
margin:20px;}
p.one {
background-color: rgb(0,0,0);
opacity: 0.5;}
p.two {
background-color: rgb(0,0,0);
background-color: rgba(0,0,0,0.5);}
</style>
</head>
<body>
<div><p class="one"></p></div>
<div><p class="two"></p></div>
</body>
</html>
