title: Positioning a button with CSS
body: <p>I have the following standard markup:</p>
  
  <pre><code>&lt;body&gt;
    &lt;header&gt;&lt;div class="wrapper"&gt;Header&lt;/div&gt;&lt;/header&gt;
    &lt;div id="create"&gt;create something&lt;/div&gt;
    &lt;div class="wrapper"&gt;Content&lt;/div&gt;
    &lt;footer&gt;&lt;div class="wrapper"&gt;footer&lt;/div&gt;&lt;/footer&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>and style:</p>
  
  <pre><code>.wrapper {
      width: 920px;
      margin: 0 auto;
      padding: 0 20px;
      text-align: left;
  }
  </code></pre>
  
  <p>The thing I am having difficulty with is positioning the "create something" button, I would like it positioned as shown below...</p>
  
  <p><img src="https://i.stack.imgur.com/6NdsI.jpg" alt="enter image description here"></p>
  
  <p>The important points to note are that the button extends to the right into infinity, and it always takes up a width of "4 squares" of the centralised area, no matter what the browser width.</p>
  
  <p>Any advice would be appreciated, thanks.</p>