#home {
    margin: 0 auto;
    width: 80%;/*原始65*/
    min-width: 500px;/*页面顶部的宽度*/
    background-color: rgba(100, 100, 100, 0.7);
    padding: 20px;
    margin-top: 50px;
    margin-bottom: 20px;
    box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3);
}
body {
    background: rgba(12, 100, 129, 1) url('https://pic.rmb.bdstatic.com/6db2b11c57223990aa3101ac455778cd.jpeg') fixed no-repeat;
    background-position: 50% 5%; 
    background-size: cover;
}