两列自适应布局是指左（右）侧有一个宽度固定的侧边栏，另一列宽度自适应。
一般我们有以下4种实现方式，废话不多说，直接上代码：
- 通过将aside浮动，然后设置main的margin来实现
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>两列自适应布局</title>
<style>
.wrapper {
height: 300px;
}
.aside {
float: left;
height: 100%;
width: 200px;
background: red;
}
.main {
margin-left: 210px;
height: 100%;
background: blue;
}
</style>
</head>
<body>
<section class="wrapper">
<aside class="aside"></aside>
<section class="main">
main main main main main main
</section>
</section>
</body>
</html>
- 将aside浮动, 再将main设置为overflow: auto，触发BFC形成独立区域，达到效果。
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>两列自适应布局</title>
<style>
.wrapper {
height: 300px;
}
.aside {
height: 100%;
width: 200px;
background: red;
margin-right: 10px;
float: left;
}
.main {
overflow: auto;
height: 100%;
background: blue;
}
</style>
</head>
<body>
<section class="wrapper">
<aside class="aside"></aside>
<section class="main">
main main main main main main
</section>
</section>
</body>
</html>
- 将aside设置为绝对定位，然后通过设置aside的width和wrapper的padding来实现
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>两列自适应布局</title>
<style>
.wrapper {
position: relative;
padding-left: 210px;
height: 300px;
}
.aside {
position: absolute;
left: 0;
width: 200px;
height: 100%;
background: red;
}
.main {
width: 100%;
height: 100%;
background: blue;
}
</style>
</head>
<body>
<section class="wrapper">
<aside class="aside"></aside>
<section class="main">
main main main main main main
</section>
</section>
</body>
</html>
- 弹性布局
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>两列自适应布局</title>
<style>
.wrapper {
display: flex;
height: 300px;
}
.aside {
width: 200px;
margin-right: 10px;
background: red;
}
.main {
flex: 1;
background: blue;
}
</style>
</head>
<body>
<section class="wrapper">
<aside class="aside"></aside>
<section class="main">
main main main main main main
</section>
</section>
</body>
</html>
