This choropleth map colors countries by economy category, using a spectral color scale to visually distinguish different economic classifications. The visualization renders geographic boundaries with `d3.geoPath` and a `geoNaturalEarth1` projection, while loading country data from a CSV file and TopoJSON world atlas. Users can zoom interactively via `d3.zoom`. A custom color legend, built with SVG circles and labels, shows the mapping between categories and colors, with hover states highlighting individual countries.