This example displays a choropleth map of India, with each state colored according to a categorical color scheme. The visualization uses the Mercator projection via `d3.geoMercator` and renders geographic boundaries with `d3.geoPath`. GeoJSON data is fetched from a GitHub Gist, parsed with `topojson`'s `feature` function, and drawn as SVG paths. The map is built with D3 v5, React, and a CSS hover effect that changes state fill colors.