This map visualization displays the global population distribution for 2018 using circles sized by population count, placed at each country's geographic centroid over a natural Earth projection. The map uses `d3.geoPath` for rendering country boundaries and `d3.scaleSqrt` for circle sizing, with a legend showing population ranges. Users can zoom and pan using `d3.zoom`. Population data comes from a UN dataset (medium variant estimates), joined with TopoJSON world geometry via `d3.json` and `d3.csv`. A color legend marks missing data countries in red.