index.html

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>Simple-Omikuji</title>
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bulma/0.7.4/css/bulma.min.css">

  <meta name="msapplication-TileColor" content="#da532c">
  <meta name="theme-color" content="#ffffff">

  <meta name="viewport" content="width=device-width, initial-scale=1">
  <script defer src="https://use.fontawesome.com/releases/v5.3.1/js/all.js"></script>
  <script src="elm.js"></script>

</head>

<body>
  <script>
    var app = Elm.Main.init();

    app.ports.copy.subscribe(function (data) {
      var ta = document.createElement("textarea")
      ta.value = data
      document.body.appendChild(ta)
      ta.select()
      document.execCommand("copy")
      ta.parentElement.removeChild(ta)
    });
  </script>
</body>

</html>