openmct/tutorials/todo/todo.html

<div class="example-todo">
    <div class="example-button-group">
        <a class="example-todo-button" data-filter="all">All</a>
        <a class="example-todo-button" data-filter="incomplete">Incomplete</a>
        <a class="example-todo-button" data-filter="complete">Complete</a>
    </div>

    <ul class="example-todo-task-list">
    </ul>

    <div class="example-no-tasks">
        There are no tasks to show.
    </div>
</div>