I just started reviewing your code, I don't think that your validation is working like you would like.
You also shouldn't be storing your bit.ly token in plain text right in the file like that. You could one of the following:
1) make a .env file that is git ignored, and then pushed onto whatever server you're running 2) use github secrets 3) figure out how to store secrets with whatever tool you use for deploying your webpage
As for the feedback you actually asked for: the header and footer look fine to me, but advanced statistics' cards don't look intentional enough to be steps. It gives off the impression that you weren't able to align the cards. It might be helpful to make the teal line be diagonal, or to be stepped.
