This example demonstrates how to construct custom legends for both color and size encodings in D3 v5 with SVG rendering. The color legend displays four ordinal categories—apple, lemon, lime, and orange—using d3.scaleOrdinal, while the size legend uses d3.scaleSqrt to map numeric tick values to circle radii. Both legends use reusable functions that bind data to groups, append circles and text, and position them with translate transforms.