1、flex盒模型：左边固定宽度，右边自适应宽度
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style>
.parent{
height:500px;
border:1px solid #222;
display:flex;
flex-flow:row;
}
.stable{
width:200px;
border:1px solid #ccc;
margin:20px;
}
.change{
flex:1;
border:1px solid #ff4400;
margin:20px;
}
</style>
</head>
<body>
<div class="parent">
<div class="stable">stable 固定宽度200px</div>
<div class="change">changeable 可变宽度</div>
</div>
</body>
</html>
2、传统模式：左边div向左浮动，右边div使用margin-left把左边div的位置留出来
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
.parent{
height: 500px;
border:1px solid #222;
}
.stable{
float: left;
height: 460px;
width: 200px;
border:1px solid #ccc;
margin:20px;
}
.change{
height: 460px;
border:1px solid #ff4400;
margin:20px 20px 20px 260px;
}
</style>
</head>
<body>
<div class="parent">
<div class="stable">stable 固定宽度200px</div>
<div class="change">changeable 可变宽度</div>
</div>
</body>
</html>
原文：https://www.cnblogs.com/CatcherLJ/p/11171729.html