A world choropleth map colors countries by their economy category, with an interactive color legend that filters which countries remain highlighted. Built with D3 v5, it uses `geoNaturalEarth1` projection with `geoPath` for geographic rendering, `zoom` for panning and scaling, and a `scaleOrdinal` with a spectral scheme for categorical colors. Data comes from TopoJSON world-atlas files merged with TSV metadata, and clicking a legend tick dims all non-matching countries.