Template:PosterGalleryCSS.css

/* ===== Poster gallery card look ===== */
.ksi-posters .gallerybox .thumb {
  border: 1px solid #777;
  background: #111;              /* dark card behind the image */
  padding: 6px;                  /* space between border and image */
  box-shadow: 0 1px 4px rgba(0,0,0,.4);
}
.ksi-posters .thumb img {
  display: block;
  width: 100%;
  height: auto;
}

/* ===== Force white for non-link caption text =====
   (higher specificity so it beats the skin defaults) */
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext p,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext span {
  color: #fff !important;
  font-size: 90%;
  padding-top: 4px;
  text-align: center;
}

/* ===== Keep links using the site's normal colors ===== */
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext a,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext a:visited,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext a:active,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext a:hover,
.mw-parser-output ul.gallery.ksi-posters li.gallerybox .gallerytext a:focus {
  color: revert !important;      /* fall back to skin/site link colors */
  text-decoration: revert;
}