I want to create something like the Page styling example but I can't figure it out how it works. I want to have a vertical grid for products. If the user clicks on the item the form on the right side will change and show the information.

The right side I can figure out, but I can't recall how the left side is build. I even can't change something in it.

Can somebody please explain how this is build.

Erwin de Rooy