.symposium-photo-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
    margin: 24px 0 48px;
}
.symposium-photo-grid .gallery-item { margin: 0; }
.symposium-photo-grid .gallery-item a { display: block; }
.symposium-photo-grid .gallery-item img {
    display: block;
    width: 100%;
    height: auto;
    aspect-ratio: 3 / 2;
    object-fit: cover;
}
.symposium-photo-grid .gallery-caption {
    margin-top: 8px;
    font-size: 14px;
}
@media (max-width: 767px) {
    .symposium-photo-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
}
@media (max-width: 479px) {
    .symposium-photo-grid { grid-template-columns: 1fr; }
}

.symposium-lightbox {
    position: fixed;
    inset: 0;
    width: 100%;
    max-width: none;
    height: 100%;
    height: 100dvh;
    max-height: none;
    margin: 0;
    padding: 64px 72px 24px;
    border: 0;
    background: rgba(0, 0, 0, .94);
    color: #fff;
}
.symposium-lightbox[open] {
    display: flex;
    align-items: center;
    justify-content: center;
}
.symposium-lightbox::backdrop { background: #000; }
.symposium-lightbox figure {
    margin: 0;
    max-width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    max-height: 100%;
}
.symposium-lightbox figure img {
    display: block;
    min-height: 0;
    max-width: 100%;
    max-height: calc(100vh - 160px);
    max-height: calc(100dvh - 160px);
    object-fit: contain;
}
.symposium-lightbox figcaption {
    padding-top: 12px;
    overflow: auto;
    text-align: center;
    font-size: 14px;
    line-height: 1.5;
    color: #fff;
}
.symposium-lightbox button {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    padding: 0;
    border: 1px solid rgba(255, 255, 255, .5);
    border-radius: 50%;
    background: #222;
    color: #fff;
    font: 36px/1 Arial, sans-serif;
    cursor: pointer;
}
.symposium-lightbox button[hidden] { display: none; }
.symposium-lightbox button:hover { background: #444; }
.symposium-lightbox button:focus-visible { outline: 3px solid #fff; outline-offset: 3px; }
.symposium-lightbox-close { top: 12px; right: 12px; }
.symposium-lightbox-prev { top: calc(50% - 24px); left: 12px; }
.symposium-lightbox-next { top: calc(50% - 24px); right: 12px; }
@media (max-width: 575px) {
    .symposium-lightbox { padding: 64px 12px 76px; }
    .symposium-lightbox-prev { top: auto; bottom: 12px; }
    .symposium-lightbox-next { top: auto; bottom: 12px; }
}