This area chart visualizes total book sales over time, using a smoothed curve to show the top selling year. The visualization plots the data from a CSV file containing book sales figures, with the area under the line filled in light blue to emphasize the trend. The code uses D3 v5’s `scaleTime`, `scaleLinear`, `line`, and `area` APIs to generate the SVG paths, with `axisBottom` and `axisLeft` for the axes. The CSV data is loaded and parsed via the `csv` function from D3.