I can't make this scrollable. This is why it was set to resize the image in the first place, so it all fits in your screen without needing to scroll.
I'll have to re-write it using a completely different approach if we want both, and I have to admit I'm tired of working on it at this point. What we have is something that works in Chrome (the old one didn't work well in Chrome) so I'm hesitant to do much more to it for the time being.