World city population
This visualization displays a world map with dots representing cities, sized by population. The map uses a natural Earth projection via `d3.geoNaturalEarth1` and `d3.geoPath`, with landmasses, graticules, and country borders rendered as SVG paths from TopoJSON data. City coordinates are projected using the same projection function, and each city is drawn as a small semi-transparent circle. The data comes from a CSV file loaded with `d3.csv` in React, and the visualization is built with React components, D3 v5, and SVG, styled with a clean, minimalist aesthetic.