This choropleth map colors world countries by economic grouping, using a spectral color scale with a custom legend. The visualization reacts to user zoom and pan gestures, redrawing country boundaries through D3’s `geoPath` and `geoNaturalEarth1` projection. Country data merges TSV attributes with TopoJSON geometry via `topojson.feature`, and hovering any country highlights it in red, while a tooltip shows its name and economic category. The project relies on D3 v5’s `scaleOrdinal`, `schemeSpectral`, and the `zoom` event helper for interactivity.