nav {
    position: sticky;
}

img {
    position: static;
}

p {
    position: absolute ;
    top: 50%;
    left: 50%;
    color:orangered;
    font-size: xx-large;
}

footer {
    position: relative;
}

.BacktoTop {
    position: fixed;
    top: 90%;
    left: 90%;
}