This interactive scatter plot visualizes the Iris dataset, comparing sepal length and width across three species. Built with vanilla D3 (v7), it uses `scaleLinear` for axes, `scaleOrdinal` for species coloring against a BBC color palette, and `csv` for data loading. The chart supports interactive highlighting via a legend, which fades non-hovered points, implemented with D3's selection joins and a `ResizeObserver` for responsive sizing.