利用BFC盒子不会和浮动元素发生重叠
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.wrap{
width: 50%;
border: 1px solid black;
}
.div1{
width: 100px;
height: 200px;
background-color: blueviolet;
float: left;
}
.div2{
background-color: brown;
height: 400px;
overflow: hidden;
}
</style>
</head>
<body>
<div class="wrap">
<div class="div1"></div>
<div class="div2"></div>
</div>
</body>
</html>