两边定宽，中间自适应布局的四种实现方法
1. 浮动法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>两边定宽，中间自适应</title>
<style type="text/css">
html,body,div{
height: 100%;
}
.left{
300px;
float: left;
background-color: red;
}
.right{
300px;
float: right;
background-color: yellow;
}
.center{
margin: auto 300px;
background-color: green;
}
</style>
</head>
<body>
<div class="left"></div>
<div class="right"></div>
<div class="center"></div>
</body>
</html>
2. 定位法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>两边定宽，中间自适应</title>
<style type="text/css">
html,body,div{
height: 100%;
}
.parent{
position: relative;
}
.left{
300px;
position: absolute;
left: 0;
background-color: red;
}
.right{
300px;
position: absolute;
right: 0;
background-color: yellow;
}
.center{
margin: auto 300px;
background-color: green;
}
</style>
</head>
<body>
<div class="parent">
<div class="left"></div>
<div class="right"></div>
<div class="center"></div>
</div>
</body>
</html>
3. 弹性盒子法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>两边定宽，中间自适应</title>
<style type="text/css">
html,body,div{
height: 100%;
}
.parent{
display: flex;
}
.left{
300px;
background-color: red;
}
.right{
300px;
background-color: yellow;
}
.center{
flex:1;
background-color: green;
}
</style>
</head>
<body>
<div class="parent">
<div class="left"></div>
<div class="center"></div>
<div class="right"></div>
</div>
</body>
</html>
4.calc计算法
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>两边定宽，中间自适应</title>
<style type="text/css">
html,body,div{
height: 100%;
}
.left{
300px;
float: left;
background-color: red;
}
.right{
300px;
float: right;
background-color: yellow;
}
.center{
calc(100% - 300px);
margin: 0 auto;
background-color: green;
}
</style>
</head>
<body>
<div class="left"></div>
<div class="right"></div>
<div class="center"></div>
</body>
</html>