#nav {
    animation-name: nav;
    animation-duration: 3.5s;
}
#nav img  {
    animation-name: nav-item;
    animation-duration: 3.5s;
}
#nav_btn {
    animation-name: nav-item;
    animation-duration: 3.5s;

}

@keyframes nav-item {
    0%, 85% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

@keyframes nav {
    0% ,70% {
        height: 100vh;
        background: black;
    }

    100% {
        height: 60px;
        background: var(--nav-bg-color);
    }

}

@keyframes scroll {
    0% ,90%{
        overflow: hidden;
    }
    100% {
        overflow: visible;
    }
}