This example displays a map of the United States with individual states rendered as green filled paths on a light blue background. It uses D3 v4 with the `d3.geoPath` and `d3.geoAlbersUsa` projection to convert TopoJSON data from the us-atlas package into SVG paths. The code loads state boundaries from a CDN, applies them via `topojson.feature`, and styles each state with a stroke and fill.