This area chart displays monthly sales growth from 2021 to 2025, with a monotonically increasing trend from 420 to 1,320 units. The visualization loads data from a CSV file, parses dates with `d3.timeParse`, and renders the area using D3's `d3.area` generator with a monotone X curve. It includes formatted axes, rotated month labels, grid lines, and clear axis labels for readability. The SVG output is styled with a light background and a shaded area against a steel-blue stroke.