.overlay {
    width: 100%;
    height: 100%;
    z-index: 99;
    position: fixed;
    top: 0;
    left: 0;
    backdrop-filter: blur(10px);
    background-color: rgba(0, 0, 0, 0.6);
    opacity: 0;
    visibility: hidden;
    transition: opacity .3s ease, visibility .3s ease;
}

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