This example displays the top 10 most populous countries as a horizontal bar chart without axes, using a fixed margin convention to inset the plot area. The chart loads data from the United Nations World Population Prospects 2019 CSV, processes it with `d3.csv`, and renders SVG rectangles scaled by population. The code uses React hooks (`useState`, `useEffect`) to fetch and filter the data, then applies `d3.scaleBand` for the y-axis categories and `d3.scaleLinear` for the x-axis range, all within an SVG canvas of 960×500 pixels.