<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>盒子</title>
<style type="text/css">
.content1{
width: 10px;
height: 10px;
background-color: #0f0;
}
.content{
width: 10px;
height: 10px;
padding: 10px;
background-color: #000;
}
.box{
width: 30px;
height: 30px;
padding: 10px;
background-color: #0f0;
}
.wrapper{
width: 50px;
height: 50px;
padding: 10px;
background-color: #000;
}
</style>
</head>
<body>
<div class="wrapper">
<div class="box">
<div class="content">
<div class="content1">
</div>
</div>
</div>
</div>
</body>
</html>
