D3 Selections Explorations - exercise
A generative animation renders a dynamic scatter of circles connected by lines, with positions, radii, and colors oscillating over time. The code imports `select` and `range` from D3 v7, builds an SVG, and a 60 FPS interval updates data via a custom `makeData` function using sine waves. Selections with `join` update circles and lines, while attributes like `cx`, `cy`, `r`, and stroke colors animate smoothly. Data is generated procedurally, with no external source.