Color and Size Legends
A row of fruit shapes demonstrates how D3.js ordinal scales map categorical data to visual channels. The `scaleOrdinal` function assigns colors and radii to apples and lemons, while circles and text labels update through data joins. As the simulation runs, fruits are removed or replaced, triggering enter, update, and exit transitions that animate position, size, and color changes. Clicking a fruit selects it, highlighting it with a black stroke. The example uses D3 v5 and renders with SVG elements and transitions.