body {
    color: #333;
    background: #dee7de;
    background: url(https://images.cnblogs.com/cnblogs_com/fzhhj/1638517/t_200202022236%E8%83%8C%E6%99%AF.jpg?a=1580610484765);
    background-size:cover;
}
#home{
   opacity: 0.8;
}