Template:Monster block/style.css

.mon-stat-block::before,
.mon-stat-block::after {
  content: "";
  display: block;
  background-image: url('/images/3/33/Stat_bar_book.png');
  background-size: 100% 100%;
  height: 6px;
  position: absolute;
  left: -3px;
  right: -3px;
}

.mon-stat-block::before {
  top: -3px;
}

.mon-stat-block::after {
  bottom: -3px;
}