body {
    font-size: 15px;
    min-height: 100%;
    background: url(//images.cnblogs.com/cnblogs_com/hkr-blog/1925773/o_2101310932501120.jpg) fixed;
    background-color: #bbb;
    position: relative;
}
#home {
margin: 0 auto;
opacity: 0.8;
width: 65%;
min-width: 1080px;
background-color: #fff;
padding: 20px;
margin-top: 30px;
margin-bottom: 30px;
box-shadow: 0 2px 6px rgba(100, 100, 100, 0.1);
}