d3 file links - problem getting it up and running

Site URL: https://khaki-saxophone-9bb5.squarespace.com/

So I am looking at this useful link.

I have added a file link to both a non-linked page AND the page I want to render the chart in (after failing with the non-linked page link).

The links themselves work a treat so the files are there ok - see url below.

I have tested d3 is working - it definitely is.

My super simple code references the file:

d3.csv("SunburstLevels.csv", function(error, data) {
  console.log(data);

  });

but I get a 404 error..

I have also tried "/s/SunburstLevels.csv" and "https://khaki-saxophone-9bb5.squarespace.com/s/SunburstLevels.csv" but these generate CORS 200 errors. 

I think maybe I have put the link in the wrong place?  Or duplicate links?  Help would be much appreciated.

Bryony