A linked choropleth map and scatter plot visualize country-level demographic and economic indicators. The map uses `d3.geoEqualEarth` and `d3.geoPath` to render world countries colored by urban population rate, while the scatter plot encodes life expectancy, birth rate, and population using `d3.scaleLinear` and `d3.scaleOrdinal`. Users can switch axes between attributes and toggle linear/log scales, triggering transitions that redraw axes and reposition points. Data is parsed from CSV and GeoJSON, with missing values handled during preprocessing.