title: Best way to adjust letter spacing every 3 chars in Ionic/Angular input box
body: <p>I'd like users to enter a code and to assist them in transcribing it I'd hope to increase the spacing between every 3rd character they type. I've seen this nicely done for credit cards having 4 character spacing. This will be for an Ionic app so the simple input box coud be replaced with a customised Ionic control.</p>
  
  <p>What methods have you used for this and what works best? 
  Open to Angular/Ionic code samples or a related web site tutorial.
  Pure CSS would be nice.</p>