This example demonstrates how to load external CSV data with D3 and manage it through React state. The app uses `d3.csv` to fetch a dataset from a GitHub gist, storing the parsed result via React's `useState` and `useEffect` hooks. While the data loads, the screen displays “loading”; once available, a custom `message` function reports the dataset’s size in kilobytes, row count, and column count as large SVG text. The visualization is minimal, focusing on the integration of D3's data-loading utilities with React's component lifecycle.