Vue 2.0 Hello World

HTML

<script src="https://unpkg.com/vue"></script>

<div id="app">
  <p :class="{active: favs.medium_title.fontWeight === 'bold'}">{{ message }}</p>
  <button @click="favs.medium_title.fontWeight = 'bold'">
  Click here
  </button>
</div>

CSS

.active{
  color:red
}

JavaScript

new Vue({
  el: '#app',
  data: {
    message: 'Hello Vue.js!',
    favs: {
    medium_title: {
    	fontWeight:''
    },
		}

  }
})