#bg{
    position: fixed;
    width: 100%;
    height: 100vh;
    background: url('/static/img/desert.jpg') no-repeat;
    background-size: cover;
    z-index: -1;
}
/* 页脚 */
footer {
    color: #888;
    margin-top: 15px;
    text-align: center;
    padding: 10px;
}
.content > h1{
    color: white;
    text-align: center;
}
.main{
    width: 80%;
    margin: 30px auto;
    padding: 30px;
    background: white;
    border-radius: 15px;
}
.layui-btn {
    width: 105px;
    border-radius: 20px;
}