<!--/* 回到顶部小工具 */-->
<th:block th:fragment="cd-top">
  <a href="#" class="cd-top" aria-label="scroll to the top of the page"></a>
  <button class="m-cd-top" title="Go to top">
    <span class="iconify" data-icon="fa:chevron-up"></span> 
  </button>
</th:block>