* { padding: 0; margin: 0; }
html { min-height: 100%; background: dimgrey; }
.gallery { text-align: center; }
.current-image-wrapper {
  background-position: 50% 50%;
  background-repeat: no-repeat;
}
.current-image-wrapper img {
  display: block;
  max-width: 100%;
  margin: 0 auto;
  opacity: 1;
  transition: opacity 0.85s;
}
.current-image-wrapper .hideme {
  opacity: 0;
  transition: opacity 0s;
}
.thumbnails li, .thumbnails a, .thumbnails img {
  display: inline-block;
  width: 3em;
  height: 4em;
  border: none;
}
.thumbnails a { outline: none; }