The header and this side menu are an example web page that might contain the shop.
All of the content on the right is dynamically added by one javascript file and one cusom HTML tag.
A footer gets dynamically added if there are items in the cart.
Look at the HTML comments for integration details.
If you look at the location bar, you will see how we always stay on the same page, but the path after the hash changes and is used by the javascript to know where you are and provide a way to link directly to a product or area of the shop.