This example displays an interactive map of U.S. counties rendered as SVG paths, with each county’s name appearing as a tooltip on hover. The map uses the `geoAlbersUsa` projection and `geoPath` from D3 v5, while TopoJSON’s `feature` method extracts county geometries from the us-atlas counties-10m.json dataset. Hovering highlights the county in green via a CSS `:hover` rule. The visualization depends on D3’s `select` and `json` utilities to fetch and bind the geographic data.