This world map visualizes population density across countries, with each nation colored on a sequential blue scale from light to dark based on its density value. The map renders in SVG using a Natural Earth projection via d3.geoNaturalEarth1 and d3.geoPath. It loads TopoJSON country boundaries from world-atlas and joins CSV population data by country ID, while a gradient legend shows the density range. Interactive hover tooltips display the country ID and its population density or “No data” when unavailable.