zulip/static/styles/lightbox.css

#lightbox_overlay {
    background-color: #19203a;

    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

#lightbox_overlay .image-preview {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    width: 100%;
    height: calc(100% - 65px - 95px);
    margin: 0px;

    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
}

#lightbox_overlay .image-preview img {
    max-height: 100%;
    max-width: 100%;

    background-color: #FFF;
    background-image:
      -moz-linear-gradient(45deg, #CCC 25%, transparent 25%),
      -moz-linear-gradient(-45deg, #CCC 25%, transparent 25%),
      -moz-linear-gradient(45deg, transparent 75%, #000 75%),
      -moz-linear-gradient(-45deg, transparent 75%, #000 75%);
    background-image:
      -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.25, #CCC), color-stop(.25, transparent)),
      -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.25, #CCC), color-stop(.25, transparent)),
      -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.75, transparent), color-stop(.75, #CCC)),
      -webkit-gradient(linear, 0 0, 100% 100%, color-stop(.75, transparent), color-stop(.75, #CCC));

    -moz-background-size: 20px 20px;
    background-size: 20px 20px;
    -webkit-background-size: 20px 20px;

    background-position: 0 0, 50px 0, 50px -50px, 0px 50px;
}

#lightbox_overlay .exit {
    float: right;

    color: rgba(255,255,255,0.8);
    font-size: 2rem;
    font-weight: 200;
    margin: 24px 20px 0px 0px;

    transform: scaleY(0.75);
    font-weight: 300;

    opacity: 0;
    pointer-events: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

#lightbox_overlay.show .exit {
    pointer-events: auto;
    opacity: 1;
}

#lightbox_overlay .image-info-wrapper {
    background-color: transparent;
}

#lightbox_overlay .image-description,
#lightbox_overlay .image-actions {
    float: left;
    margin: 20px 20px;
}

#lightbox_overlay .image-actions {
    float: right;
}

#lightbox_overlay .image-actions a {
    margin-bottom: 0px;
    margin-top: 0px;
}

#lightbox_overlay .image-actions .icon {
    font-size: 1.1rem;
    display: inline-block;
}

#lightbox_overlay .image-actions .icon .text {
    font-size: 0.9rem;
}

#lightbox_overlay .image-actions span:nth-of-type(2) {
    position: relative;
    top: 1px;
}

#lightbox_overlay .image-actions .open span:nth-of-type(2) {
    top: 2px;
}

#lightbox_overlay .image-description {
    /* approx width of screen minus action buttons on the side. */
    width: calc(100% - 260px);
    /* add some extra margin top and remove some bottom to keep the
       height the same. and vertically center the text with the buttons. */
    margin-top: 25px;
    margin-bottom: 15px;

    font-size: 1.3rem;
    color: #fff;
}

#lightbox_overlay .image-description .title {
    display: inline-block;
    vertical-align: top;

    font-weight: 500;
    line-height: normal;
    max-width: calc(100% - 210px);

    /* Required for text-overflow */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#lightbox_overlay .image-description .user::before {
    margin-right: 5px;
    content: "\2014";
}

#lightbox_overlay .player-container {
    height: calc(100% - 65px - 95px);
    display: flex;
    text-align: center;
    justify-content: center;
    align-items: center;
}

#lightbox_overlay .player-container iframe {
    /* maintain 16:9 ratio. */
    width: calc((100vh - 65px - 95px) * 16 / 9);
    height: 100%;
    margin: auto;
}

#lightbox_overlay .image-description .user {
    max-width: 200px;
    display: inline-block;
    vertical-align: top;
    font-weight: 300;
    line-height: normal;
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: pre;
}

#lightbox_overlay .center .arrow {
    display: inline-block;
    vertical-align: top;
    margin-top: 25px;
    padding: 5px 10px;

    color: #fff;
    font-size: 1.8em;
    font-weight: 100;

    transform: scaleY(2);
    cursor: pointer;

    opacity: 0.5;
    transition: all 0.3s ease;
}

#lightbox_overlay .center .arrow:hover {
    opacity: 1;
}

#lightbox_overlay .center .image-list {
    position: relative;
    display: inline-block;
    padding: 15px 0px 12px 0px;
    height: 50px;
    font-size: 0px;

    max-width: 40vw;
    overflow: hidden;
    white-space: nowrap;
}

#lightbox_overlay .center .image-list .image {
    display: inline-block;
    vertical-align: top;
    width: 50px;
    height: 50px;
    margin: 0px 2px;

    background-color: rgba(240, 240, 240, 0.2);
    opacity: 0.5;

    background-size: cover;
    background-position: center;
    cursor: pointer;
}

#lightbox_overlay .image-list .image.selected {
    opacity: 1;
}

.image-actions .button {
    font-size: 0.8rem;
    min-width: inherit;
    padding: 4px 10px;
    border: 1px solid rgba(255,255,255,0.6);
    background-color: transparent;
    color: #fff;
    border-radius: 4px;
}

.image-actions .button:hover {
    background-color: #fff;
    color: #19203a;
}

.image-actions a.button {
    text-decoration: none;
}

.button .download {
    top: 1px;
}

#lightbox_overlay .clear-float {
    clear: both;
}

@media only screen and (min-device-width : 320px) and (max-device-width : 736px) {
    #lightbox_overlay .image-actions {
        display: none !important;
    }

    #lightbox_overlay .image-description {
        width: calc(100% - 100px);
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    #lightbox_overlay .image-description .title {
        max-width: calc(100% - 60px);
    }

    #lightbox_overlay .center .image-list {
        max-width: 80vw;
    }

    #lightbox_overlay .player-container iframe {
        /* maintain 16:9 ratio. */
        width: 100%;
        height: calc((100vw) * 9 / 16);
        margin: auto;
    }
}