This reusable D3 scatter plot visualizes the classic Iris dataset, plotting petal length on the x-axis against sepal length on the y-axis for 150 flower samples. Built with vanilla HTML, CSS, and the D3 v6 library, it uses `scaleLinear`, `extent`, `axisLeft`, and `axisBottom` to map data points to an SVG canvas. Circles are rendered via `selectAll` and `join`, with the visualization filling the full browser window and updating to any screen size.