title: Border image with opacity
body: <p>I have this:</p>
  
  <pre><code>.striped-border {
      border: 8px solid transparent;
      border-image: url(../img/stripes.png) 9 round;
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/TQ1t3.png" rel="noreferrer"><img src="https://i.stack.imgur.com/TQ1t3.png" alt="Content with a border-image"></a></p>
  
  <p>What I want:</p>
  
  <p><a href="https://i.stack.imgur.com/HDN1Z.png" rel="noreferrer"><img src="https://i.stack.imgur.com/HDN1Z.png" alt="enter image description here"></a></p>
  
  <p>Is it possible to apply an opacity to the <strong>border-image only</strong> and not the content?</p>