<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
      [v-cloak] {
        display: none;
      }
    </style>
  </head>
  <body>
    <div id="root">
      <input type="text" id="input" v-model="message" />
      <p v-cloak>The value of the input is: {{ message }}.</p>
    </div>

    <script src="https://unpkg.com/vue@2.1.3/dist/vue.js"></script>
    <script>


      const app = new Vue({
        el: '#root',
        data: {
          message: "Hello world",
        }
      });

    </script>
  </body>
</html>