* {
    margin: 0px;
    padding: 0px;
}
 
html,
body {
    height: 100%;
    overflow: hidden;
}
 
body {
    background: url("https://static.codemao.cn/coco/player/unstable/r185r3Kbh.image/jpeg?hash=FsA0hEhphevQgbVhPC2z-iMpazAR") no-repeat;
    background-size: 100% 100%;
    position: relative;
}
 
.background {
    width: 400px;
    height: 400px;
    margin-top: 120px;
    margin-left: 100px;
    background-color: rgba(102, 102, 102, 0.8);
    border-radius: 20px;
    position: relative;
}
 
.head {
    width: 100%;
    height: 50px;
    line-height: 50px;
    color: white;
    font-size: 28px;
    margin-top: 20px;
    text-align: center;
    position: absolute;
}
 
.zhanghao {
    width: 100%;
    height: 40px;
    color: white;
    font-size: 18px;
    text-align: center;
    margin-top: 100px;
    position: absolute;
}
 
.zhanghao input {
    height: 25px;
    outline: none;
}
 
.mima {
    width: 100%;
    height: 40px;
    color: white;
    font-size: 18px;
    text-align: center;
    margin-top: 160px;
    position: absolute;
}
 
.mima input {
    height: 25px;
    outline: none;
}
 
.yanzhengma {
    width: 100%;
    height: 40px;
    color: white;
    font-size: 18px;
    text-indent: 75px;
    margin-top: 220px;
    position: absolute;
}
 
#input {
    width: 50px;
    height: 25px;
    outline: none;
}
 
#code {
    width: 80px;
    height: 30px;
    font-size: 20px;
    font-family: Arial;
    font-style: italic;
    font-weight: bold;
    letter-spacing: 2px;
    color: blue;
    border: 0;
    background-color: white;
}
 
.btn {
    width: 100%;
    height: 40px;
    color: white;
    font-size: 18px;
    text-indent: 85px;
    margin-top: 280px;
    position: absolute;
}
 
.btn2 {
    width: 100%;
    height: 40px;
    line-height: 40px;
    color: white;
    font-size: 18px;
    text-align: center;
    margin-top: 340px;
    position: absolute;
}
 
.returnSenLia {
    text-decoration: none;
    color: white;
}
 
.zhucea {
    text-decoration: none;
    color: red;
}
 
.denglu {
    width: 100px;
    height: 40px;
    color: white;
    font-size: 18px;
    background-color: red;
    border-radius: 10px;
    border: 0px;
    outline: none;
}