This choropleth map colors countries by economic classification using an ordinal color scale with a spectral palette. The visualization includes a custom SVG color legend showing category colors and labels. Built with D3 v5, it uses `d3.geoNaturalEarth1` for projection, `d3.geoPath` for rendering, and applies zoom interactions. The map loads TopoJSON data from world-atlas and joins it with TSV metadata to assign country properties. Hovering highlights individual countries in red.