title: Shadow for a background image
body: <p>I have a <code>span</code> element as follows - </p>
  
  <pre><code>&lt;span class="tick"&gt;&lt;/span&gt;
  </code></pre>
  
  <p>This basically generates a "tick" for a checkbox. </p>
  
  <p>The CSS is as follows - </p>
  
  <pre><code>input[type="checkbox"] + span &gt; span.tick {
      display: block;
      position: absolute;
      z-index: 2;
      top: -3px;
      left: -1px;
      width: 20px;
      height: 20px;
      background-repeat: no-repeat;
      background-image: url(/content/dam/oe_tick.png);
      background-size: 18px;
      background-position: 3px 1px;
  }
  </code></pre>
  
  <p>I want to add a shadow around the image - <code>/content/dam/oe_tick.png</code>.
  Is it possible?</p>
  
  <p>Thanks in Advance!</p>