A choropleth map colors countries by economy using a D3 v5 ordinal color scale with a spectral scheme. The visualization uses the `d3.geoPath` and `d3.geoNaturalEarth1` projection to render geographic boundaries from TopoJSON world-atlas data, with a legend built via a custom `colorLegend` function. Hovering highlights a country in pink, and a zoom interaction is implemented with `d3.zoom`. The map is rendered as SVG with a dark blue ocean background.