index.html

<!DOCTYPE html>
<html>
<head>

  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width,initial-scale=1">
  <title>basic-month-name</title>

  <script src="../webcomponentsjs/webcomponents-lite.js"></script>
  <link rel="import" href="../basic-framed-content/basic-framed-content.html">
  <link rel="import" href="basic-month-and-year.html">

  <style>
    body,
    button,
    input {
      font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
      font-size: 15px;
    }

    body {
      margin: 0;
    }

    basic-framed-content {
      padding: 2em;
    }
  </style>

  <script>
    document.addEventListener('WebComponentsReady', function() {
      document.body.removeAttribute('unresolved');
    });
  </script>
</head>

<body unresolved>
<basic-framed-content>
  <basic-month-and-year></basic-month-and-year>
</basic-framed-content>
</body>

</html>