Using Fancybox with CodePenIO

I’m working on the portfolio project and have used Fancybox previously. I think I am going to go with it again but I have some questions:

  1. What do I need to do in CodePenIO for Fancybox to work within that platform?
  2. If anyone has used fancybox, where would I go to adjust the size of the thumbnails to make them smaller?
  3. I also want on thumbnail to represent a whole project, like multiple screen shots etc etc - not just one creative sample. Any tips on accomplishing this with fancybox would be greatly appreciated.