Circles on a Map
This visualization maps global population data by country, using circle area to represent population size for 2018. Users can pan and zoom across a natural Earth projection, and hover to reveal exact population counts. The visualization uses d3.geoPath, d3.geoNaturalEarth1, d3.scaleSqrt, and d3.zoom, with data from a CSV joined to TopoJSON world atlas geometry. A size legend and color legend are rendered as SVG, with circles and country borders styled for clarity.