Two custom legends demonstrate ordinal color and quantitative size encodings in D3 v7. The color legend uses `scaleOrdinal` to map fruit categories to distinct fills, while the size legend uses `scaleSqrt` to map numeric ticks to circle radii. Both are rendered as SVG groups with circle and text elements, updated through D3’s selection-merging API. The example highlights reusable legend construction patterns within a single static visualization.