#home{
        opacity: 0.7;
        /* margin: 0 auto; */
        /* box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3); */
}
div{
        /* background-position-y: bottom; */
        id="top-nav"
}
body{
        background: url("https://images.cnblogs.com/cnblogs_com/blogs/718709/galleries/2073832/o_211204080505_p1.png")fixed;
        background-size: cover;
        background-repeat: no-repeat;
        background-position: initial;
        font-family:initial;
        font-size: 24px;
        
}