This choropleth map colors countries by economic classification using an ordinal color scale derived from `d3.scaleOrdinal` and `schemeSpectral`. The map renders with `d3.geoNaturalEarth1` projection and `d3.geoPath`, while country geometries and names come from TopoJSON and TSV data loaded via `Promise.all`. A semi-transparent legend built from `d3.scaleOrdinal` domains shows color categories, and `d3.zoom` enables panning and zooming over the SVG. Hovering highlights individual countries in red.