title: Div not 100% width of browser
body: <p>My div will not stretch the full width of the browser, it stops short on both ends by about 10px.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.header {
    position: relative;
    background-color: #088ed7;
    width: auto;
    height: 20px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="header"&gt;...&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>I've tried both <code>auto</code> and <code>100%</code> but still get the same outcome.</p>