Choropleth Map
A choropleth map colors countries of the world according to their economic classification, using a spectral color scale. The visualization is rendered as an SVG and supports zooming. Built with D3 v5, it leverages `geoPath` and `geoNaturalEarth1` for map projection, and `scaleOrdinal` with `schemeSpectral` for coloring. Data comes from the world-atlas package (50m TSV and JSON files), loaded via `loadAndProcessData`, with countries displayed as paths and a custom legend.