Since Tiki 2 or so, there has been an extra div around module boxes, with the class box-shadow. Now in Tiki 3.0 there are more such divs in tiki.tpl, for adding additional styling, as follows, and a switch to activate them all:

  • div id="main-shadow"

Just outside div="main" (surrounds the whole visible page)

  • div id="header-shadow"

Just outside div id="header" (surrounds the page header and its logo, site title, top menu, etc.)

  • div id="middle-shadow"

Just outside div id="middle" (surrounds the middle of the page containing the left, center and right columns)

  • div id="tiki-center-shadow"

Just outside div id="tiki-center" (surrounds the center-column content)

  • div id="footer-shadow"

Just outside div id="footer" (surrounds the footer (bottom bar) area

These divs are activated to be styled by checking|ticking the checkbox on the Look and Feel admin page. They are then ready to receive styling from themes that recognize them.

Activating this option will have a global effect (the site's templates/tiki.tpl file will present the additional divs), but presumably they are ignored if a theme doesn't specify anything for the above selectors.

Ref: http://doc.tiki.org/Shadow+Layers