popup.html

<!doctype html>
<html>
  <head>
    <title>Asana Filtering</title>
    <script src="popup.js"></script>

    <style>
      body {width: 170px;}
      div#columnFilters,div#userFilters {
        border: 1px dotted red;
        padding: 5px;
        margin: 7px;
      }

      h1 {
        font-size: 14px;
      }

      ul {
        list-style: none;
        padding-left: 5px;
        margin: 0;
      }
    </style>
  </head>
  <body>
    <div id="columnFilters">
      <h1>columns</h1>
    </div>
    <div id="userFilters">
      <h1>assignees</h1>
      <ul id="assigneeList">
        <li><input type="checkbox" checked="checked" id="deselectAllCheckbox"/><strong>(De)select all</strong></li>
        <li><input type="checkbox" checked="checked" id="unassignedCheckbox"/>Unassigned</li>
      </ul>
    </div>
  </body>
</html>