#overlay{
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    background-color: rgba(0,0,0,0.2);
    z-index: 5000;
    position: fixed;
    opacity: 0;
    visibility: hidden;
    transition: 0.15s all ease-in-out;
}
#overlay.show{
    opacity: 1;
    visibility: visible;
}