This bar chart displays the top 10 countries by estimated 2020 population, using horizontal bars ranked from largest to smallest. The visualization loads CSV data from a GitHub gist, which is parsed with `d3.csv` and structured in React state via a custom `useData` hook. The x-axis uses a `d3.scaleLinear` range mapped to population values, while the y-axis uses a `d3.scaleBand` for country categories. SVG elements are generated by React components for axes and marks, with `d3.format` applied to abbreviate tick labels.