A heatmap-like scatterplot visualizes a time series of x and y positions as a smooth, green path with a Catmull-Rom curve, overlaid with individual circle marks. The code loads CSV data from a GitHub gist, parses numeric coordinates, and uses D3 v7 scales, axes, and the `d3.line` API with `curveCatmullRom.alpha`. The SVG rendering fills the browser window, with axis tick labels styled via CSS.