title: How to center a div with a relative width?
body: <p>I have a <code>&lt;div&gt;</code> which is styled as following:</p>
  
  <pre><code>.content{
      width: 70%;
  }
  </code></pre>
  
  <p>To center a div, there is the possibility to set the margin to auto (<code>margin: 0 auto;</code>) but this only works if I have a fixed size(e.g. 400px). So how can I center my div with relative width?</p>