<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Vanilla Javascript DropDown Menu Example</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" type="text/css" href="style.css">
  </head>
  <body>
    <div id="menu-dropdown">Menu &#9660;</div>
    <div id="menuDiv-dropdown" class="invisible">
      content<br>content<br>content
    </div>

  <script src="vanilla-javascript-dropdown-menu-example.js"></script>
  </body>
</html>