聊聊三栏布局----左右定宽，中间自适应。
效果图：
圣杯布局
<!DOCTYPE html>
<html>
<head lang="en">
<title>圣杯</title>
<style>
.container{
padding:0 200px 0 180px;
height:100px;
}
.left{
float:left;
width:180px;
height:100px;
margin-left:-100%;
background:red;
position:relative;
left:-180px;
}
.main{
float:left;
width:100%;
height:100px;
background:blue;
}
.right{
float:left;
width:200px;
height:100px;
margin-left:-200px;
background:green;
position:relative;
right:-200px;
}
</style>
</head>
<body>
<div class="container">
<div class="main">middle</div>
<div class="left">left</div>
<div class="right">right</div>
</div>
</body>
</html>
双飞翼布局
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title>双飞翼</title>
<style>
.main{
float:left;
width:100%;
height:100px;
background:blue;
}
.left{
float:left;
width:180px;
height:100px;
margin-left:-100%;
background:red;
}
.right{
float:left;
width:200px;
height:100px;
margin-left:-200px;
background:green;
}
.inline{
margin:0 200px 0 180px;
}
</style>
</head>
<body>
<div class="main">
<div class="inline">middle</div>
</div>
<div class="left">left</div>
<div class="right">right</div>
</body>
</html>注意：一定要在要在main中再包裹一个<div>并设置它的margin:0 180px 0 200px。
Flex布局
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Flex</title>
<style>
.flex {
display: flex;
flex-flow: row;
}
.left{
width: 180px;
height: 100px;
background-color: red;
}
.main{
flex: 1;
height: 100px;
background-color: blue;
}
.right {
width: 200px;
height: 100px;
background-color: green;
}
</style>
</head>
<body>
<div class="flex">
<div class="left">left</div>
<div class="main">middle</div>
<div class="right">right</div>
</div>
</body>
</html>最重要的还是要理解浮动和负margin技术以及width:100%。