This choropleth map displays world countries colored by economy category using an ordinal spectral color scale. Clicking a legend category filters the map by highlighting countries in that category and dimming all others; clicking again clears the filter. The visualization uses D3 v5 APIs including `geoNaturalEarth1`, `geoPath`, `zoom`, and `scaleOrdinal` on SVG paths, with country data loaded from the world-atlas TopoJSON and TSV files. A legend built with `colorLegend` updates opacity and triggers interactive filtering.