A choropleth map of world countries colored by economy category, with an interactive legend that filters the map when clicking a category. Hovering a country displays its name and value via a tooltip. The visualization uses D3 v5 with d3.geoNaturalEarth1 projection, d3.geoPath for rendering, and d3.zoom for pan and zoom. Data comes from the world-atlas TopoJSON and TSV files, processed with topojson.feature and d3.tsv.