三栏式布局，两边固定，中间自适应

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <meta name="viewport" content="width=device-width, initial-scale=1.0">
 6     <meta http-equiv="X-UA-Compatible" content="ie=edge">
 7     <title>Document</title>
 8     <style>
 9         body, h1{padding: 0;margin: 0;}
10         header{width: 100%;height: 100px;background-color: green;}
11         footer{width: 100%; height: 100px;background-color: darkslategray;}
12         .left,.right,.center{float: left; height: 500px;}
13         .left,.right{ position: relative; width: 200px;}
14         .container{
15             overflow: hidden;
16             padding: 0 200px;
17         }
18         .center{
19             background-color: greenyellow;
20             width: 100%;
21         }
22         .right{
23             background-color: #3a9;
24             right: -200px;
25             margin-left: -200px;
26         }
27         .left{
28             background-color: #f00;
29             left: -200px;
30             margin-left: -100%;
31         }
32     </style>
33 </head>
34 <body>
35     <header><h1>header</h1></header>
36     <div class="container">
37         <div class="center">center</div>
38         <div class="left">left</div>
39         <div class="right">right</div>
40     </div>
41     <footer><h1>footer</h1></footer>

42 </body> 
43 </html>