A choropleth map of world countries, colored by economic classification using an ordinal color scale from `d3.scaleOrdinal` and `schemeSpectral`. Hovering highlights a country and reveals a tooltip with its name and economy type. The map uses `d3.geoNaturalEarth1` projection and `d3.geoPath` for rendering, with zoom support via `d3.zoom`. Data comes from World Atlas TopoJSON and TSV files; a custom color legend shows the ordinal categories.