title: How to change the opacity of the border without changing its color
body: <p>I'm going to change opacity of input's border when it's disabled using SCSS. But border color is coming from variable:</p>
  
  <pre><code>$borderColor: #5985dc;
  
  .my-input {
    border: 1px solid $borderColor;
  }
  .my-input:disabled {
    border-color: ???;
  }
  </code></pre>
  
  <p>... or is there any way to change the color to half-transparent version?</p>