2栏布局 右侧自适应
flex
grid
table
float
<style >
body{
height: 400px;
}
.son1{
width: 20%;
height: 100%;
float: left;
}
.son2{
margin-left: 20%;
height: 100%;
}
</style>
<body>
<div class="son1" style="background-color: #d2e085;"> A </div>
<div class="son2" style="background-color: #7cdbe4;"> B </div>
</body>