*{margin: 0;padding: 0; outline: none;}
body{height: auto;}
nav{background: #000; width: 100%;}
nav img{width: 150px;margin:0 auto;display: block;position: relative;}
.denglu{width: 300px;height: 300px;background: #fff;position: absolute;top: 50%;margin-top: -150px; left: 50%;margin-left: -150px;border-radius: 20px;}
.denglu h1{color: #00CED1;text-align: center;padding: 20px 0;}
.denglu input{width: 250px;height: 30px;margin: 0 auto;display: block;border:none;border-bottom: 1px solid #777;margin: 20px;}
.denglu a{color: #00CED1;text-decoration: none;margin-left: 20px;}
.anniu{background: #00CED1;color: #fff;border-radius: 20px;border: none;}