title: Expecting RBRACE? What is CSS Lint talking about?
body: <p>CSS Lint thinks there is something wrong here. And so does the W3C CSS Validator. They are probably right and I am wrong, but can someone please help me understand why this is wrong?</p>
  
  <p><strong>CSS:</strong></p>
  
  <pre><code>.my-class {
      width:  calc(((100% - 15%) / 3 - 1px) * 3 + 10%); /* for 3 columns */
  }
  </code></pre>
  
  <p><strong>Error message:</strong></p>
  
  <pre><code>Expected RBRACE at line 2, col 22.
  </code></pre>
  
  <p>By the way, browsers seem to be more on my side.</p>