But the CSS template itself doesn't include any coding for them to work.
It probably does. In many cases it's just an id="..." or name="..." in the div tag that links the div with a javascript or PHP file which activates js or PHP code to do something.
There is probably a link in the head section to the js file like
<script type="text/javascript" src="expandcollapse.js"></script>
which you missed
and some PHP code like
<?php include ("iescrollbar.inc"); ?> which you won't see because it is processed at the server before downloading.
Also do advanced web developers write their own code to update pages online (like blogs or front pages), edit offline then reupload, or use wordpress/moveable type etc.
They probably use a CMS (Content Management System) like Joomla or Drupal which allows edits of password-protected sections without risk of disturbing the code.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.