Making an Advent Calendar

Hi there.

I'm interested in creating a simple Squarespace site and would love a bit of advice.

Basically I want to create a really straightfoward advent calendar, much like the attached picture.

I have an image that I've created and 24 different images for the different days.

I'd like to be able to let people click on the doors as Christmas goes on and have them open up and reveal a picture within, so It will need 24 clickable buttons in different places all over the page that hopefully open up in situ, not needing to click through to a different page.

Does anyone have any ideas about how I might do that?

Thanks in advance