1👍
Your console have the following errors:
Mixed Content: The page at 'https://pure-woodland-72284.herokuapp.com/' was loaded over HTTPS, but requested an insecure stylesheet 'http://fonts.googleapis.com/css?family=Lobster+Two:400,700italic'. This request has been blocked; the content must be served over HTTPS.
Hence you are getting 'Uncaught ReferenceError: $ is not defined'
error since you did not really imported your libraries
So I’m guessing that you have imported your scripts (jquery,d3.tip,cssfonts) from their cdn and used http while importing. Try importing them with https and see if that solves your problem
👤eko
Source:stackexchange.com