This example displays a map of Europe and North Africa with city locations marked by circles and labeled with their names. It uses a Mercator projection via `d3.geoMercator` and renders the country boundaries as SVG paths through `d3.geoPath`. City data from `cities.csv` is plotted as circles and text labels, with the map styled using custom CSS classes. The visualization loads both the GeoJSON country boundaries and the CSV data concurrently using `Promise.all`.