A choropleth map colors countries by their economy category using a categorical color scale. The map is rendered as SVG with geographic paths projected via `d3.geoNaturalEarth1` and encoded with `d3.geoPath`, while panning and zooming are handled by `d3.zoom`. A legend, built with custom code, displays color-coded circles in `d3.scaleOrdinal`’s `schemeSpectral` range. Data comes from World Atlas TopoJSON and TSV files, loaded with `d3.json` and `d3.tsv`, and each country shows its name and value on hover via a `<title>` element.