<!DOCTYPE html>
<html lang="en" >
<head>
<meta charset="UTF-8">
<title>CSS3浮动占位符登录框按钮发光特效</title>
<link rel="stylesheet" href="css/style.css">
</head>
<body>
<div class="login-box">
<h2>登录</h2>
<form>
<div class="user-box">
<input type="text" name="" required="">
<label>用户名</label>
</div>
<div class="user-box">
<input type="password" name="" required="">
<label>密码</label>
</div>
<a href="#">
<span></span>
<span></span>
<span></span>
<span></span>
提交
</a>
</form>
</div>
</body>
</html>