This visualization presents a world choropleth map coloring countries by economic classification using a spectral color scale, with an interactive legend that filters highlighted countries on click. Built with D3 v5, it employs `d3.geoNaturalEarth1` for projection, `d3.geoPath` for rendering, and `d3.zoom` for panning and zooming. Country data comes from the World Atlas TopoJSON and TSV files, while the legend uses `d3.scaleOrdinal` and `d3.schemeSpectral`. Hovering over a country turns it red, and the legend’s clickable ticks dim non-selected categories.