This example visualizes the top 10 countries by 2020 population using a horizontal bar chart rendered as SVG. The chart uses a `scaleBand` for country categories on the y-axis and a `scaleLinear` for population magnitudes on the x-axis, with a `rect` per data row. It loads UN population data via `d3.csv` and builds the visualization with React hooks (`useState`, `useEffect`) and D3 v5 scales.