title: Handle font size for multiple screen size windows 8 metro apps
body: <p>I have a text of font size 14.<br>
  On smaller screens it's visible but on bigger screens it becomes smaller.<br>
  How do I handle this?<br>
  On android we have <code>SP</code> which adjust the font size according to the screens.<br>
  Is there anything similar to this in windows 8 ?</p>