nextcloud/apps/gallery/css/styles.css

div#gallery_list {
  margin: 90pt 20pt;
}

div#gallery_album_box {
  width: 200px;
  text-align: center;
  border: 0;
  float: left;
  margin: 5pt;
}

div#gallery_album_box h1 {
  font-size: 12pt;
  font-family: Arial;
}

div#gallery_album_cover {
  width: 199px;
  height: 199px;
  border: solid 1px black;
}