When creating a new Poole project, you can choose a theme to start from. Here's a showcase of the available themes.
A rather minimal theme with only a few lines of CSS. Use this if you want to build your own style from scratch.
A responsive theme using the CSS and JS framework Bootstrap. Use this to benefit from a grid system and many useful widgets.
Another responsive theme, using the CSS and JS framework Foundation. It also provides you with a grid system and various useful widgets.