CSS - overlay modal

Question

.global-overlay-modal {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    transition: opacity 350ms;
    // visibility: hidden;
    opacity: 1;
    z-index: 9999999;
    .img-popup {
        &-detail {
            width: 100%;
            margin: 11% auto 0;
            text-align: center;
            img {
                width: 55% !important;
                height: auto !important;
            }
        }
    }
}