This example shows a choropleth map of the world’s countries, colored by economic classification using a spectral color scale. The map renders as SVG and supports mouse hover highlighting, which changes the fill of individual countries to dark green. It loads geographic data from the world-atlas TopoJSON and matches it with country names and economy values from a TSV file. The visualization uses d3.geoPath with a d3.geoNaturalEarth1 projection, applies a d3.scaleOrdinal for colors, and enables pan and zoom through d3.zoom.