This interactive choropleth map visualizes countries colored by economic grouping using an ordinal color scale. Users can click a legend swatch to highlight matching countries, dimming others, or click the map background to clear the filter. The visualization is built with D3 v5, using `geoNaturalEarth1` and `geoPath` for map projections and `scaleOrdinal` for colors. Data comes from the world-atlas TopoJSON and TSV files, with rendering in SVG.