SemanSemantic-UItic-UI/server/partials/dimmer-demo.html

<div class="ui demo page dimmer">
  <div class="content">
    <div class="center">
      <h2 class="ui inverted icon header">
        <i class="mail icon"></i>
        Dimmer Message
        <div class="sub header">Dimmer sub-header</div>
      </h2>
    </div>
  </div>
</div>