.overlay {
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    position: fixed;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    transition: 0.2s ease;
    z-index: 2;
}

.overlay.active {
    visibility: visible;
    opacity: 1;
}