tasks/simpleTasks/page.html

<!DOCTYPE html>
<html>
<head>
<?!= HtmlService.createHtmlOutputFromFile('stylesheet').getContent(); ?>
</head>
<body>

<h1>Simple Tasks</h1>
<p>
  This application allows you to view your <a href="https://mail.google.com/tasks/canvas" target="_blank">Google Tasks</a>,
  mark them as complete or incomplete, and add new tasks.
</p>

<label for="tasklist">Select a task list: </label>
<select id="tasklist">
  <option>Loading...</option>
</select>

<fieldset id="tasks-panel">
  <legend>Tasks</legend>

  <form name="new-task" id="new-task">
    <label for="task-title">Add a new task:</label>
    <input type="text" name="task-title" id="task-title" />
    <input type="submit" name="add" id="add-button" value="Add" />
  </form>

  <ul id="tasks">
    Loading...
  </ul>
</fieldset>

<?!= HtmlService.createHtmlOutputFromFile('javascript').getContent(); ?>

</body>
</html>