パンくずドロップダウン

<nav class="d03-02-11-crumb">
          <span class="d03-02-11-node">
            <button class="d03-02-11-link" type="button">ホーム</button>
          </span>
          <span class="d03-02-11-sep">/</span>
          <span class="d03-02-11-node">
            <button class="d03-02-11-link" type="button">サービス <i>▾</i></button>
            <ul class="d03-02-11-drop">
              <li>Web制作</li><li>SEO対策</li><li>保守運用</li>
            </ul>
          </span>
          <span class="d03-02-11-sep">/</span>
          <span class="d03-02-11-node d03-02-11-cur">料金プラン</span>
        </nav>

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