title: Possible to pass arguments to CSS classes?
body: <p>I have a div like this:</p>
  
  <pre><code>&lt;div class="center small-top-margin"&gt;
    &lt;%= rails code %&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>where `small-top-margin' is as follows:</p>
  
  <pre><code>.small-top-margin {
      margin-top: 2em;
  }
  </code></pre>
  
  <p>Is there a way to pass an argument to a css class such that </p>
  
  <p><code>class="top-margin(2)</code> #=> <code>margin-top: 2em;</code><br>
  <code>class="top-margin(5)</code> #=> <code>margin-top: 5em;</code>
  etc..</p>
  
  <p>or even better</p>
  
  <p><code>class="margin(top, 2)</code> #=> <code>margin-top: 2em;</code></p>
  
  <p>I've included <code>Rails</code> tags in case there's a way to do this through rails, although a purely css/sass solution would be better.  </p>