This example displays a choropleth-style map of Bulgaria, rendered as green landmasses with yellow borders over a graticule grid and blue background. Built with React and D3 v6, it uses `geoMercator` projection and `geoPath` to draw the geographic features, while `geoGraticule` generates the latitude and longitude lines. The map data is loaded from a remote GeoJSON file via `d3.json` and processed with topojson's `feature` method. Color styling is applied through CSS classes, with gray indicating missing data regions.