/* Boilerplate CSS */
#show-acn, 
#show-reg {
    cursor: pointer;
    color: red;
}

.btn-show-image-holder {
    justify-content: center;
    display: flex;
}

/* The real CSS */

.image-viewer {
    background-color: #000;
    position: fixed;
    display: block;
    opacity: 1;
    height: 100%;
    width: 100%;
    left: 0;
    top: 0;
    z-index: 2000;
}

.image-viewer>figure>img {
    transform: translate(-50%, -50%);
    position: fixed;
    max-height: 100%;
    max-width: 100%;
    left: 50%;
    top: 50%;
}

.image-viewer>figure>figcaption {
    background: rgba(0, 0, 0, 0.5);
    text-align: center;
    position: absolute;
    padding: 10px;
    color: #fff;
    z-index: 1;
    right: 0;
    bottom: 0;
    left: 0;
}

.image-viewer>#iv-top-btn-holder>.iv-btn {
    background-color: transparent;
    position: relative;
    margin-top: 10px;
    font-size: 25px;
    cursor: pointer;
    border: none;
    color: #fff;
    z-index: 1;
}

.image-viewer>#iv-top-btn-holder>#back-button {
    margin-left: 15px;
    float: left;
}

.image-viewer>#iv-top-btn-holder>#fullscreen-button {
    margin-right: 15px;
    float: right;
}

.iv-hide {
    animation: hide 1s forwards;
}

@keyframes hide {
    from {
        visibility: visible;
        opacity: 1;
    }

    to {
        visibility: hidden;
        opacity: 0;
    }
}