title: CSS class starting with number is not getting applied
body: <p>I'm trying to create a webpage that contains images. However, I want all the images to be the same size and in the same format. I have the following CSS class which applies to a div and centers and sizes the image:</p>
  
  <pre><code>.img-container {
      border: thin solid #C4C4C4;
      border-radius: 10px;
      overflow: hidden;
      margin-left: auto;
      margin-right: auto;
  }
  </code></pre>
  
  <p>However, my images will have different dimensions throughout the page. Thus I want to have separate classes for just height and width, like so:</p>
  
  <pre><code>.200-200 {
      width: 200px;
      height: 200px;
  }
  </code></pre>
  
  <p>When I apply both of these classes to the div as follows:</p>
  
  <pre><code>&lt;div class="img-container 200-200"&gt;&lt;img&gt;&lt;/div&gt;
  </code></pre>
  
  <p>the height and width don't seem to apply. Is there anything I can do to have these classes separated? </p>