This example displays a scatter plot of the Iris dataset, plotting sepal length against sepal width and highlighting individual points in red on hover. The visualization uses D3 v7 APIs including `csv` for data loading, `scaleLinear` and `extent` for scaling, and `axisLeft`/`axisBottom` for axes. Circles are rendered as SVG elements via `selectAll().data().join()`, with a fixed radius and black fill. The chart fills the entire browser window, and axes are positioned using margins derived from `innerWidth` and `innerHeight`.