This example shows a scatter plot of sleep duration versus stress level, with each point colored by gender, drawn from a Kaggle sleep health dataset. It uses React to manage the SVG container and d3.csv to load and parse the data. The reusable viz.js function builds the chart with d3-scale, d3-axis, and d3-shape, including a Tableau10 ordinal color scale, a legend, and hover tooltips rendered as SVG `<title>` elements.