.template-thumbnail-area {
  background-color: #f7f7f7;

  /* チェッカーボード柄背景 */
  /* background-image:
      linear-gradient(45deg, #f0f0f0 25%, transparent 25%),
      linear-gradient(135deg, #f0f0f0 25%, transparent 25%),
      linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
      linear-gradient(135deg, transparent 75%, #f0f0f0 75%);
  background-size: 20px 20px;
  background-position: 0 0, 10px 0, 10px -10px, 0px 10px; */
}

.template-thumbnail-area-inner {
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

.template-thumbnail-area img.thumbnail {
  max-width: calc(600px - 1.5rem * 2);
  max-height: calc(600px - 1.5rem * 2);
  width: 100%;
  height: auto;
  object-fit: contain;

  /* 透過サムネイルは背景色を白で塗りつぶす */
  background-color: #fff;
}