.dotted-line {
    border: none;
    border-top: 3px dotted #004999; /* 点の太さと色 */
    height: 0;
    background: none;
  }

  /* 点の間隔を調整したい場合（dash-styleなら） */
  .dashed-custom {
    border: none;
    height: 0;
    background: none;
    border-top: 3px dashed #666;
    border-image: repeating-linear-gradient(to right, #666 0 6px, transparent 6px 12px) 100;
  }