This example visualizes the countries of Europe as a static SVG map using a Mercator projection centered on the continent. The code loads GeoJSON feature data via `d3.json` and renders each region as a `path` element using `d3.geoPath` with the projection. React and D3 v5 are used together to manage the document, while TopoJSON is loaded but not directly applied in the visible logic. Country boundaries appear as grey strokes with white fills, set through SVG attributes.