</body>
</html>
绝对定位<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style type="text/css">
body {
margin: 0;
padding: 0;
}
.left {
position: absolute;
left:0px;
left: 300px;
height: 100px;
background-color: red;
}
.right {
position: absolute;
right:0px;
width: 300px;
height: 100px;
background-color: blue;
}
.center {
position: absolute;
left:300px;
right:300px;
background-color: black;
height: 100px;
}
</style>
</head>
<body>
<div class="father">
<div class="left">1</div>
<div class="center">2</div>
<div class="right">3</div>
</div>
</body>
</html>
CSS优化(1)压缩
(2)属性连写： font ：font-style font-weight font-size
(3)继承：font clolr
(4) CSS放入Head中，减少reflow repaint
