源代码 ：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>开源教程(ossoft.cn)</title> <style> input[type=text] { width: 130px; box-sizing: border-box; border: 2px solid #ccc; border-radius: 4px; font-size: 16px; background-color: white; background-image: url('https://www.ossoft.cn/images/mix/searchicon.png'); background-position: 10px 10px; background-repeat: no-repeat; padding: 12px 20px 12px 40px; -webkit-transition: width 0.4s ease-in-out; transition: width 0.4s ease-in-out; } input[type=text]:focus { width: 100%; } </style> </head> <body> <p>搜索输入框带动画:</p> <form> <input type="text" name="search" placeholder="搜索.."> </form> </body> </html>
运行结果