This example shows a horizontal bar chart of the top 10 most populous countries in 2019. The chart renders SVG rectangles scaled by population using D3’s `scaleLinear` and `scaleBand`. It loads CSV data via `d3.csv`, uses React hooks (`useState`, `useEffect`) to manage state, and manually draws axes and gridlines with D3’s `scaleLinear.ticks` and React JSX, without relying on `d3.axisLeft` or `d3.axisBottom`.