This choropleth map colors countries by economic classification using a spectral color scale, with a legend showing the ordinal categories and hover effects highlighting individual countries. The map is rendered as an SVG using d3.geoPath with a geoNaturalEarth1 projection, while d3.zoom enables interactive panning and zooming. Data is loaded from the world-atlas TopoJSON and TSV files via topojson.feature, and the color legend is built custom with d3.scaleOrdinal and d3.schemeSpectral.