This choropleth map visualizes countries colored by their economic classification, using a spectral color scale to distinguish categories. The map renders geographic boundaries as SVG paths via `d3.geoPath` and a Natural Earth projection. Data is loaded from the World Atlas TopoJSON and TSV files, merged by country ID, then assigned to the `d3.scaleOrdinal` color scale. A custom legend shows color swatches with labels, and hovering highlights individual countries in red. Interaction includes zoom and pan through the `d3.zoom` event, which applies an SVG transform.