This choropleth map visualizes the distribution of salaries by country, using a blue color scale to indicate aggregated mean salary values. The map renders geographic boundaries from a GeoJSON file ("world_map.geojson") onto an SVG canvas. It loads salary data from a hardcoded array, aggregates entries via `d3.rollups` and `d3.mean`, and colors each country path with a sequential interpolator (`d3.interpolateBlues`). Countries without matching salary data appear gray. The visualization relies on `d3.geoPath` for path generation and D3's `d3.json` loader to fetch the map data.