This fork of a choropleth map visualizes World Bank GDP per capita data for 2020 across countries worldwide. The map colors each country using a quantile color scale with a YlGnBu sequential scheme, with gray filling regions lacking data. The visualization loads GeoJSON topology from the world atlas and CSV data, processing both through `Promise.all` before rendering with `d3.geoNaturalEarth1`, `d3.geoPath`, and `d3.geoGraticule`. The code implements a reusable map component that updates through a state management pattern using `d3.select` and `d3.scaleQuantile`.