/* ===== 共通：チェックボックスは視覚的に隠す ===== */
  .ac-container input[type="checkbox"],
  .ac-sub input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    pointer-events: none;
  }

  /* =========================================
     第1階層（親アコーディオン）
     ========================================= */
  .ac-container > div {
    border-bottom: 1px solid #ddd;
  }

  .ac-container > div > label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    padding: 14px 4px;
    font-weight: bold;
    user-select: none;
    position: relative;
  }

  .ac-container > div > label::after {
    content: "";
    width: 10px;
    height: 10px;
    margin-left: 8px;
    flex-shrink: 0;
    border-right: 2px solid #666;
    border-bottom: 2px solid #666;
    transform: rotate(-45deg);
    transition: transform 0.25s ease;
  }

  .ac-container > div > input:checked + label::after {
    transform: rotate(45deg);
  }

  .ac-container > div > article {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 4px;
  }

  .ac-container > div > input:checked ~ article {
    max-height: 2000px; /* 内側にサブアコーディオンが増える分、大きめに確保 */
    padding: 0 4px 16px;
  }

.ac-label-content {
  display: flex;
  align-items: center;
  gap: 6px; /* 画像とテキストの間隔 */
}

.ac-label-content img {
  width: 17px;  /* お好みのサイズに調整 */
  height: 17px;
  flex-shrink: 0;
}

  /* =========================================
     第2階層（サブアコーディオン）
     ac-sub は article の中に置く
     ========================================= */
  .ac-sub {
    margin: 8px 0 4px;
    border-left: 3px solid #ddd;
    padding-left: 12px;
  }

  .ac-sub > div {
    border-bottom: 1px dashed #ddd;
  }

  .ac-sub > div > label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    padding: 10px 4px;
    font-weight: normal;
    color: #444;
    user-select: none;
    position: relative;
  }

  /* サブは矢印を少し小さく・色を薄めにして親と区別する */
  .ac-sub > div > label::after {
    content: "";
    width: 8px;
    height: 8px;
    margin-left: 8px;
    flex-shrink: 0;
    border-right: 2px solid #999;
    border-bottom: 2px solid #999;
    transform: rotate(-45deg);
    transition: transform 0.25s ease;
  }

  .ac-sub > div > input:checked + label::after {
    transform: rotate(45deg);
  }

  .ac-sub > div > article {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 4px;
    font-size: 0.95em;
    color: #555;
  }

  .ac-sub > div > input:checked ~ article {
    max-height: 500px;
    padding: 0 4px 12px;
  }