This example shows a multi-series line chart comparing Sales, Profit, and Expenses across a 150-sample dataset, with each metric drawn as a distinct colored path (steelblue, green, and orange) over a light gray grid. It is built using React and D3 v7, using `d3.csv` to load the data and `d3.scaleLinear`, `d3.axisBottom`, `d3.axisLeft`, and `d3.line` for scales, axes, and path generation. The SVG chart includes labels, a legend, and is rendered with a fixed width and height.