.lb-cancel {
  background: url(./plugin_file.php?file=ImageThumbnail/loading.gif) no-repeat;
}

.lb-nav a.lb-prev {
  background: url(./plugin_file.php?file=ImageThumbnail/prev.png) left 48% no-repeat;
}

.lb-nav a.lb-next {
  background: url(./plugin_file.php?file=ImageThumbnail/next.png) right 48% no-repeat;
}

.lb-data .lb-close {
  background: url(./plugin_file.php?file=ImageThumbnail/close.png) top right no-repeat;
}