body{
background:url("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1566905765350&di=d3cfff9bec6beaefe06d1a36b1dc435b&imgtype=0&src=http%3A%2F%2Fb-ssl.duitang.com%2Fuploads%2Fitem%2F201601%2F02%2F20160102120613_BA5wK.jpeg") no-repeat;
background-size:cover;
background-attachment:fixed;
}
#home{
opacity:0.9;
}