This example demonstrates two reusable D3 legend components rendered as SVG: a color legend for ordinal scales and a size legend for quantitative scales. The color legend displays fruit categories as colored circles with labels, while the size legend visualizes numeric values through scaled circle radii. Both components use D3’s selection join pattern with `selection.enter` and `selection.merge` to update elements. The size legend relies on `scaleSqrt.ticks` to generate tick values, while the color legend maps ordinal domain values to a range of colors via `scaleOrdinal`.