This example visualizes the relationship between wine pH and total sulfur dioxide concentration as an area chart, with the area filled in steel blue and axes labeled accordingly. The chart filters data from a WineQT CSV hosted on GitHub, computed with D3's `d3.area` and `d3.scaleLinear`. It renders in SVG via D3 v6, using `d3.csv` for data loading, `d3.axisBottom` and `d3.axisLeft` for axes, and includes a legend rectangle. The accompanying text explains a comparison of machine learning models for stock volatility forecasting.