This example uses D3 v7 to render an interactive scatter plot of the Iris dataset, loaded via `d3.csv` from a GitHub gist. The visualization maps petal length on the x-axis and sepal length on the y-axis using `scaleLinear` and `extent`, with points colored by species via `scaleOrdinal` and `schemeCategory10`. SVG circles are bound to data with `join`, and each carries a `<title>` tooltip. Hovering triggers a CSS transition that enlarges the circle’s radius, while `axisLeft` and `axisBottom` add labeled axes.