Essential Design

The default template is called "kattemplate". It's plain and grey. It's a common style, with the banner and a navigation bar across the top, the content and one or more sidebars below, and a navbar/footer which goes across the bottom. Shaped like an very overful sandwich.

It can be done with right sidebar, left sidebar, or a sidebar on each side. This design is useful if you want to have a wider banner/logo or other things that take up the width of the page.