title: Material-UI app bar title styling
body: <p>is it possible to style the AppBar from Material-UI title, not inline way?
  I've a css file seperate and I would like to change the size of title for example.</p>
  
  <p>sth like this: </p>
  
  <pre><code>.app-bar title {
      font-size: 120px !important;
  }
  </code></pre>
  
  <p>Thank you :)</p>