lightgallery/css/lg-relative-caption.css

.lg-relative-caption .lg-outer .lg-sub-html {
  white-space: normal;
  bottom: auto;
  padding: 0;
  background-image: none;
}

.lg-relative-caption .lg-outer .lg-relative-caption-item {
  opacity: 0;
  padding: 16px 0;
  transition: 0.5s opacity ease;
}

.lg-relative-caption .lg-outer .lg-show-caption .lg-relative-caption-item {
  opacity: 1;
}