(FCC) Data Visualization Certification - Project 4 - Choropleth Map
This choropleth map displays the percentage of adults with a bachelor’s degree or higher across U.S. counties, using a sequential color scale to encode educational attainment. It renders GeoJSON county boundaries via `d3.geoPath` and an SVG projection, while a tooltip (shown when hovering over a county) reports the exact education rate. The visualization loads two JSON datasets concurrently through `Promise.all`, fetching county topology and education statistics from freeCodeCamp’s CDN, then binds the education data to the map features using D3’s data joins. The page relies on D3 v5 for all geographic and data manipulation.