This example visualizes the classic Iris dataset as a scatter plot, comparing petal length on the x-axis with sepal length on the y-axis for 150 flowers. The visualization uses D3 v7 with vanilla JavaScript to load the CSV data via `d3.csv`, parse the numeric fields, and render SVG circles positioned through `d3.scaleLinear` scales. Axes are drawn using `d3.axisLeft` and `d3.axisBottom`, while the chart fills the entire browser viewport with margins applied around the plot area.