第二十五节 屏幕适配之em单位

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
 6     <title>Document</title>
 7     <style type="text/css">
 8         body{
 9             margin: 0
10         }
11         .box1{
12             font-size: 12px;
13             width: 20em;
14             height: 10em;
15             background-color: gold;
16             /* 宽默认是body的宽 高等于16*10 */
17         }
18     </style>
19 </head>
20 <body>
21     <div class="box1">1</div>
22     <div class="box2"></div>
23 </body>
24 </html>
原文地址:https://www.cnblogs.com/kogmaw/p/12492786.html