Website of IABM Textbook is empty?

[BigBook]

Hi,
Recently, I have been learning classic textbooks “Introduction to agent based modeling”, but there is no content on its website “https://www.intro-to-abm.com/”. if it has been migrated to another address, if anyone knows, I hope to let you know, thank you!

[jzkelter]

You see a blank page? When I go there I see this:

[BigBook]

This is the web page I see here, and nothing happened after clicking these buttons either. I tried to opening it with different browsers, but the result was the same.