1 <html lang="en">
2 <head>
3 <meta charset="UTF-8">
4 <meta name="viewport" content="width=device-width, initial-scale=1.0">
5 <meta http-equiv="X-UA-Compatible" content="ie=edge">
6 <title>box-盒模型</title>
7 <style>
8 div{
9 width: 200px;
10 height: 200px;
11 margin: 10px;
12 padding: 5px;
13 background-color: aliceblue;
14 border: 1px solid black;
15 }
16 div:first-child{
17 box-sizing: content-box;
18 }
19 div:last-child{
20 box-sizing:border-box;
21 }
22 </style>
23 </head>
24 <body>
25 <div> content-box</div>
26 <div>border-box</div>
27 </body>
28 </html>
来源：https://www.cnblogs.com/yuanxiangguang/p/11318000.html