This example demonstrates two custom legend types rendered as SVG: a color legend mapping ordinal fruit categories to distinct hues, and a size legend using a square-root scale to encode numeric values through circle radii. The color legend uses `d3.scaleOrdinal` with domains for apple, lemon, lime, and orange, while the size legend employs `d3.scaleSqrt` with tick marks generated from the scale. Both legends are built procedurally using custom functions (`colorLegend` and `sizeLegend`) that append grouped circles and text elements, with spacing and offset parameters controlling layout. The visualization is constructed with D3 v5 and rendered entirely in SVG, with styling applied via CSS classes.