This example demonstrates reusable legend components for both ordinal color scales and quantitative size scales, rendered as SVG. The color legend uses `d3.scaleOrdinal` to map fruit categories to colors, while the size legend uses `d3.scaleSqrt` to map numeric tick values to circle radii. Both legends are drawn using custom selection-based functions that append SVG groups, circles, and text elements with d3’s selection API. The code runs in d3 v5 and renders within a single SVG element.