body {
      font-family: system-ui, sans-serif;
      background: #f5f5f7;
      margin: 0;
      padding: 0;
    }

    header {
      background: #222;
      color: #fff;
      padding: 12px 20px;
    }

    header h1 {
      margin: 0;
      font-size: 18px;
    }

    /* --- Accordion --- */
    .accordion-item {
      margin: 12px;
      border-radius: 6px;
      overflow: hidden;
      box-shadow: 0 1px 4px rgba(0,0,0,0.1);
      background: #fff;
    }

    .accordion-header {
      width: 100%;
      text-align: left;
      padding: 12px 16px;
      background: #0078d4;
      color: #fff;
      border: none;
      cursor: pointer;
      font-size: 15px;
      font-weight: bold;
    }

    .accordion-header:hover {
      background: #005fa3;
    }

    .accordion-body {
      display: none;
      padding: 16px;
      background: #fff;
      border-top: 1px solid #ccc;
    }

    .accordion-body.active {
      display: block;
    }

    /* --- Form elements --- */
    textarea, input[type="text"], input[type="number"] {
      width: 100%;
      box-sizing: border-box;
      padding: 6px;
      margin-top: 4px;
      border: 1px solid #ccc;
      border-radius: 4px;
      font-size: 13px;
    }

    .checkbox-group label {
      display: inline-block;
      margin-right: 12px;
      margin-bottom: 6px;
      font-size: 13px;
    }

    .prompt-output {
      width: 100%;
      min-height: 180px;
      font-family: "Cascadia Code", Consolas, monospace;
      font-size: 12px;
      padding: 8px;
      border-radius: 4px;
      border: 1px solid #ccc;
      background: #fafafa;
      resize: vertical;
    }

    button.primary {
      background: #0078d4;
      color: #fff;
      border: none;
      padding: 8px 12px;
      border-radius: 4px;
      cursor: pointer;
      margin-top: 8px;
    }

    button.primary:hover {
      background: #005fa3;
    }

  /* ▼ 出力プロンプト専用ヘッダー色 */
.accordion-header.output-header {
  background: #38b51f;  /* 好きな色に変更可能 */
}

.accordion-header.output-header:hover {
  background: #c6dd44;
}