Why Doesn't the Edit in Browser option work for the examples on https://get.foundation/sites/docs/

Hi, going through the documentation at Foundation for Sites 6 Docs there is an abundance of example code along with what it is supposed to look like. These examples offer an option to “Edit in Browser” but I have yet to find one where the output in the edit in browser feature matches what is shown in the example code. It seems like none of the CSS works. For example, see the screenshot below.

The horizontal menu becomes a standard styled list when using the Edit in Browser option.

Is this really how it is supposed to work?

Thanks.