This example displays a choropleth map of Swedish counties, using a teal fill with gray borders, alongside a cyan network of interior boundaries. Built with React and D3 v5, the visualization uses `geoMercator` for projection and `geoPath` to render the geographic features. The source data is a TopoJSON file of simplified Swedish counties, processed with the `topojson` library’s `feature` and `mesh` functions to generate both the county shapes and their shared interior borders.