A world choropleth maps country-level numeric values from a CSV file onto a natural Earth projection, using a plasma color scale and gradient legend to encode magnitude. The visualization links ISO numeric country codes to TopoJSON geometry from the world-atlas dataset, rendering with D3 v7’s `d3.geoPath`, `d3.geoNaturalEarth1`, and `d3.scaleSequential`. Hovering over a country reveals a tooltip with its name and value, while countries without data appear in a muted blue.