We believe in simple clean awesomeness.
The web should be light or dark - each and every website should support light and dark themes - you can rest assured your website / wiki reactor will too - checkout the theme selector at the top.
We use Bootstrap 2.3 for this clean awesome look, so you know your pages will look great.
Besides the dark/light themes, we have a growing selection of available layouts:
To select a layout, go to your reactor admin page and edit it - inside you will look for a section called "website" and in there add this line (or replace it if the layout was already configured):
and then save the page.
See getbootstrap.com/2.3.2/scaffolding.html#gridSystem to learn about the div9 and div12... or just experiment with them.