This example displays a world map using the spherical Mercator projection, rendered as SVG paths through d3.geoPath. The visualization distinguishes landmasses in dark red, country borders in teal, graticules in light gray, and the ocean sphere in off-white. It loads geographic data from the world-atlas TopoJSON file, converting it with topojson.feature and topojson.mesh. The React component uses the d3.geoMercator and d3.geoGraticule APIs within a marks subcomponent to draw each geographic layer.