title: CSS can't select classes/id's with numbers in it?
body: <p>Why can't you use numbers in CSS and is there another way of doing the job? I have the following code:</p>
  
  <pre><code>&lt;div class="center 400-width" id="position"&gt;
      &lt;div class="" id="header"&gt;
          Header
      &lt;/div&gt;
      &lt;div class="" id="content"&gt;
          Content
      &lt;/div&gt;
      &lt;div class="" id="footer"&gt;
          Footer
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>The CSS selects the class <code>400-width</code> which means the container gets a width of <code>400px</code>. And the <code>background-color</code> is for checking if it's true.</p>
  
  <pre><code>.400-width{
      width:400px;
      background-color:blue;
      color:white;
  }
  </code></pre>
  
  <p>It doesn't happen right now as you can see <a href="http://jsfiddle.net/gekkeabt/XQjE4/1/" rel="nofollow noreferrer">here</a></p>
  
  <p>I solved the problem by replacing <code>400-</code> by <code>four</code>. So it becomes <code>fourwidth</code>.</p>