You could certainly hard code it into your wp theme, but that's really not a great way to integrate it.
It would be best to just code it into a plugin, but that may prove frustrating since it's giving you a little struggle right now.

The Yii url you gave outlines the how-to quite clearly, but doing that in WP is trickier.
You can hard code it, and many people would, but that would be a poor way to do it.

It would be faster and better to look at this premium plugin (not aff link), that already does the same thing and so much more. I've used many times, and it's a quality plugin.

I'm glad to guide you through it, but the time investment for a less then optimal solution is not really beneficial to you.

Yii Foundation 3 : Yii Foundation 3 - Reveal Site

The original Foundation can be found here:

Foundation: The Most Advanced Responsive Front-end Framework from ZURB

And a Wordpress Theme built on ZURB Foundation can be found here:

http://themefortress.com/reverie/

I am using Foundation and Reverie on many projects... I love ZURB Foundation, one of the best 'frameworks' around.

So if you want to go with Foundation for WP, try Reverie.

Github link: https://github.com/milohuang/reverie

Demo: http://themefortress.com/demo/

The Reveal plugin is part of the WP theme, too ;-)

I will suggest you that just code it into a plugin,

No problem.