title: How to add offset material-ui Grid
body: <p>I'm trying to make a small 'Item added' popup dialog on material-ui using it's Grid system. But i can't figure out how to add offset to the Grid. I'm trying to achieve something similar to Bootstrap's <code>col-sm-10 offset-1</code> using</p>
  <p><code>&lt;Grid container justify='center' alignItems='center' item xs={10}&gt;</code></p>
  <p>But it doesn't work. My solution was to add an empty column before and after my content, like:</p>
  <pre><code>&lt;Grid item xs={1}&gt;&lt;/Grid&gt;
  &lt;Grid item xs={10} justify='center' alignItems='center'&gt;Content&lt;/Grid&gt;
  &lt;Grid item xs={1}&gt;&lt;/Grid&gt;
  </code></pre>
  <p>Do I have to do it like this? I can't figure out why justify and alignItems are not working.
  Here is the code on codesandbox:
  <a href="https://codesandbox.io/s/item-added-jx9ri" rel="noreferrer">https://codesandbox.io/s/item-added-jx9ri</a></p>
  <p>Thanks for the help!</p>