This choropleth map visualizes average GDP per capita by country from 1970 to 2017, with each nation shaded on a logarithmic green color scale based on its value. Hovering over a country dims all others, highlights the selected region, and reveals a tooltip with the country’s name and GDP. Built with D3 v6, it uses `d3.geoMercator` and `d3.geoPath` to project and draw the map from a simplified GeoJSON, while the data from a CSV is joined to the topology for coloring. Animated transitions control opacity and tooltip visibility.