Fiat Site in the Gallery, how was the slideshow made?

Fiat Site in the Gallery, how was the slideshow made?

Hello there, my question concerns this mobile site in the gallery,

http://www.jqmgallery.com/2012/04/14/fiat-spain/

I like the slideshow effect they have there, I was able to pull it out and get it to work, but I do not know how to modify it.  It seems that clicking the arrows changes the left attribute by a certain amount,

<ul class="home-slideshow" style="width: 1650px; left: -375px;"></ul>

But I didn't see any javascript on their page that corresponded to that, it appears that they modified the jquery css to get this functionality, but that seems strange to me.

Anyway, if someone could better explain this effect that would be nice, I was thinking about making a cat slideshow :)