This choropleth map colors countries by economic category and supports interactive filtering through a clickable legend. Selecting a legend category highlights matching countries while dimming others, and clicking again clears the selection. The map uses d3.geoNaturalEarth1 projection with d3.geoPath, while d3.zoom enables panning and zooming. Color categories are assigned via d3.scaleOrdinal with CSS classes, and the legend’s click handler toggles the filter. Data comes from world-atlas TopoJSON and TSV files, rendered as SVG paths with tooltips showing country names and values.