title: css - Adding a class to all section elements
body: <p>I want to add the 'foo' class to all <strong>section</strong> elements on a page.  I understand that I could simply:</p>
  
  <pre><code>&lt;section class="foo"&gt;...&lt;/section&gt;
  </code></pre>
  
  <p>on every <strong>section</strong> element, but there are <strong>many</strong> sections.  Is there an easier way to do this?  (note: foo is a 3rd party class).</p>
  
  <p>I also realise that I could style it like this:</p>
  
  <pre><code>section { font-style:...; color:...; /* all foo class styles */ }
  </code></pre>
  
  <p>but then I am duplicating the 'foo' class, which is against my principles.  If the 'foo' class changes I want my sections to change 'automatically' in the same way, without me having to edit my duplicate style.</p>