<div id="firstApp">
   Counter: {{ count }}
</div>
#firstApp {
  display: inline-block;
  padding: 10px;
  font-size: 36px;
  font-family: 'Helvetica Neue', 'Open Sans', sans-serif;
}

#firstApp button {
  background: #4c82ff;
  border: 0;
  color: #FFF;
  font-size: 16px;
  margin-top: 6px;
  padding: 5px 10px;
  border-radius: 3px;
  display: block;
  width: 100%;
}
var firstApp = new Vue({
  el: '#firstApp',
  data: {
    count: 0
  }
});

setInterval(function() {
  firstApp.count += 1;
}, 1000);

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.10/vue.min.js