This example displays a population dataset from the UN’s 2019 estimates, rendered as an interactive React application. The code imports D3’s `csv` loader to fetch data from a GitHub Gist, while `arc` and `pie` are used to generate a chart based on the loaded values. The visualization uses React hooks like `useState` and `useEffect` to manage asynchronous data loading and state. The UI presents a styled message, “Hello HTML!”, alongside the data-driven chart, combining static HTML/CSS with dynamic JavaScript and D3 functionality.