This example displays a world map rendered as a green SVG using a Mercator projection. It loads country boundaries from the world-atlas TopoJSON dataset and converts them to GeoJSON with topojson.feature. The code uses d3.geoPath and d3.geoMercator to define the projection, and appends a path for each country to an SVG element with a light blue background. The map is built with D3 v4 within a React-compatible HTML page.