HTML CSS Modal popup on image

G'day all, been quite some time since i've been doing coding and have used the services of a coder for years, but he seems to be missing in action just right when I need him.

Here is the gist. I'm wanting to use this script from here: https://html5up.net/multiverse
But instead of it opening up the image like the script does, i'm wanting to open it up with information that i've defined elsewhere (like a price list). The way it opens up is great, just don't want to see a pic :(
However, i'm having no luck other than just getting the image to display. When i've changed the href link to a webpage, the website just hangs (does nothing) until I press Esc.

So any help would be greatly appreciated. The rest I should be somewhat fine with as i've got pre-existing code that looks up database/table values. It's just this first bit that has me stumped.