This example demonstrates how to create custom legends for both ordinal color scales and continuous size scales in D3 v5. It shows a color legend with four fruit categories (apple, lemon, lime, orange) rendered as colored circles, and a separate size legend with scaled circles representing values from 0 to 10. The code builds reusable legend components using D3’s `scaleOrdinal`, `scaleSqrt`, and `selection.call()`, rendering everything as SVG elements with styled fonts and circle strokes defined in CSS.