This example shows a stacked area chart of course enrollment by category (Technology, Business, Design) over time, where the colored regions represent the number of students enrolled in each category per year. The chart is rendered as an SVG using D3 v7, with `d3.csv` loading the data from a GitHub gist, `d3.area` generating the stacked paths, and `d3.scaleLinear` mapping the year and enrollment values. Axes are added via `d3.axisBottom` and `d3.axisLeft`, with a legend and axis labels included.