photoprism/frontend/src/css/viewer.css

#p-photo-viewer {
    z-index: 1500;
}

#p-photo-viewer .pswp__caption__center {
    text-align: center;
    max-width: 80%;
    margin: 0 auto;
    font-size: 14px;
    padding: 10px;
    line-height: 20px;
    color: #E0E0E0;
    font-weight: 400;
}

#p-photo-viewer .pswp__caption__center .v-icon,
#p-photo-viewer .pswp__caption__center a {
    font-weight: 400;
    font-size: 17px;
    text-decoration: none;
    padding-left: 4px;
}

#p-photo-viewer .pswp__caption__center .description {
    font-weight: 300;
    font-size: 13px;
}

#p-photo-viewer .pswp__caption__center .taken {
    font-weight: 300;
    font-size: 13px;
}

#p-photo-viewer .pswp__taken {
    padding: 10px;
    line-height: 20px;
    font-size: 14px;
    color: #E0E0E0;
    font-weight: 300;
    width: auto;
    height: 44px;
    position: relative;
    background: none;
    cursor: none;
    overflow: visible;
    -webkit-appearance: none;
    display: block;
    border: 0;
    margin: 0;
    float: left;
    opacity: 0.75;
    -webkit-transition: opacity 0.2s;
    transition: opacity 0.2s;
    -webkit-box-shadow: none;
    box-shadow: none;
}

@keyframes fadeInOut {
    0% {
        opacity:0;
    }
    30% {
        opacity:1;
    }
}
  
.slide_show {
    animation-name: fadeInOut;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-duration: 2s;
    animation-direction: alternate;
}