This interactive choropleth map displays the world’s countries colored by their economic classification, with a color legend that filters the map when clicked. Clicking a legend value highlights corresponding countries and dims all others; clicking again clears the filter. Hovering a country reveals its name and value in a tooltip. Built with D3 v5, it uses `d3.geoNaturalEarth1` for projection, `d3.geoPath` to render country paths, and a custom `colorLegend` module for the clickable legend. Data comes from the world-atlas TopoJSON and TSV files, rendered as SVG.