.ngg-galleryoverview { 
  display: block; 
}

.ngg-gallery-thumbnail {
  display: block;
  float: left;
  margin: 0;
}

.ngg-gallery-thumbnail-box {
  display: block;
  float: left;
}

.ngg-gallery-thumbnail img {
  border: 1px solid #A9A9A9;
  margin: 4px 0 4px 5px;
  padding: 4px;
}