1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="utf-8"> 5 <title></title> 6 <style> 7 .box{ 8 width: 200px; 9 border: 1px solid #000000; 10 background-color: red; 11 } 12 .box input{ 13 border: 0; 14 margin: 0; 15 width: 200px; 16 height: 30px; 17 background-color: #fff; 18 *float: left; 19 } 20 </style> 21 <!-- 22 解决方案： 23 给input元素添加float 24 --> 25 </head> 26 <body> 27 <div class="box"> 28 <input type="text" /> 29 </div> 30 </body> 31 </html>