Code Snippet  HTML:
<button class="button" id="open-modal">Open Modal</button>

<div id="modal" class="modal">
  <div class="modal-content">
    <p>Some text in the Modal..</p>
    <span class="close-modal">
      <button id="close-modal" class="button button-warning modal-toggle">X</button>
    </span>
  </div>
</div>