body{
background: url(//images.cnblogs.com/cnblogs_com/17lhf/1638324/o_200127095044636424843288430428.png);
background-size:100%;
background-repeat: no-repeat;
 background-attachment:fixed;
}
#home {
margin: 0 auto;
opacity: 0.9;
width: 80%;
min-width: 1080px;
background-color: #fff;
padding: 20px;
box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3);
}
#main{
width:100%;
}
#mainContent{
width: 75%;
}