This area chart shows how the average time spent surfing varies by age, with a red semi-transparent filled area overlaid on a line. The visualization groups individual-level CSV data by age and computes the mean surfing time per age group. Built with D3 v7, the chart uses `d3.csv`, `d3.group`, and `d3.mean` to aggregate data, then renders an SVG path via the `d3.area()` generator. Linear scales map age and time values to x and y axes, with axis labels and a title drawn as SVG text elements.