body {
    margin: 0;
    font-size: 1.2rem;
    min-height: 100%;
    font-family: Smart Quotes,-apple-system,BlinkMacSystemFont,Helvetica Neue,PingFang SC,Microsoft YaHei,Source Han Sans SC,Noto Sans CJK SC,WenQuanYi Micro Hei,sans-serif;
    background-color: #bbb;
    position: relative;
    background: url(//images.cnblogs.com/cnblogs_com/packy/1643923/o_200208115112dls.jpg) fixed;
}
#home {
margin: 0 auto;
opacity: 0.5;
width: 65%;
min-width: 1080px;
background-color: #fff;
padding: 30px;
margin-top: 50px;
margin-bottom: 50px;
box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3);
}