An interactive scatterplot shows GDP variation across years for selected countries, with circles colored by country and clickable legend entries that highlight a chosen nation while dimming others. Built with D3 v5, it uses `scaleLinear` for axes, `axisBottom` and `axisLeft` with gridlines, and an SVG renderer. Data is loaded from a CSV and updated via a `render` function that re-calls the scatterplot and color legend components.