<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="description" content="Calculator">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Calculator</title>
    <link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">
  </head>
  <body>
    <div id="app"></div>
    <script src="bundle.js"></script>
  </body>
</html>

<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="description" content="Calculator">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Calculator</title>
  </head>
  <body>
    <div id="app"></div>
    <script async src="bundle.js"></script>
  </body>
</html>
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">

Enhance performance according to PageSpeed
Enhance performance according to PageSpeed
