This scatter plot visualizes the relationship between free and total sulfur dioxide levels in wine samples, with each point colored and shaped according to wine quality rating. The code loads a WineQT dataset via `d3.csv`, scales both axes with `d3.scaleLinear`, and renders points as SVG paths generated using `d3.symbol()` with distinct shapes mapped to quality values. A custom color scale assigns a unique hue to each quality tier, while unlisted values fall back to gray. The chart uses `d3.axisBottom` and `d3.axisLeft` for labeled axes within an SVG container.