<div class="backdrop"></div>

<div id="my-modal" class="modal">
  <div class="modal-header">
    标题
  </div>

  <div class="modal-content">
    内容
  </div>

  <div class="modal-footer">
    <button class="btn" data-dismiss="modal">
  关闭
</button>
  </div>
</div>

<button class="btn" data-toggle="modal" data-target="#my-modal">
  开启模态框
</button>