.overlay {
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    position: fixed;
    background: #222;
    z-index: 9999;
    opacity:0.5;
}


.overlay-content {
    left: 50%;
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
}