Here is an example of what i want to achieve: https://www.spoiledchild.com/
Been trying to find examples of this type of code and I havent got any. New to JS(like newbie) but I really need to understand this part of code for a small site I am working on and I cant really seem to understand how to even make this type of code work. Can anyone help with some example code? Would be much appreciated and thank you.