<div xmlns:th="https://www.thymeleaf.org"
     th:fragment="widget (sidebar)"
     th:class="'card widget toc ' + ${sidebar.hide} + ' is-hidden-all'">
    <div class="card-title">
        <i th:class="${#strings.defaultString(sidebar.icon, 'ri-book-2-line') + ' card-title-label'}"></i><span th:text="${#strings.defaultString(sidebar.title, '目录')}"></span>
    </div>
    <div class="card-content toc-content">
    </div>
</div>