Renders a before/after comparison with a vertical divider that sweeps from left to right using interpolate(). The left side shows 'Before' content (desaturated) and the right shows 'After' content (vibrant). A circular handle rides the divider line.
Before/after content, divider speed, and styling are configurable. Use for photo editing demos, design iterations, renovation reveals, or any visual transformation that benefits from a direct side-by-side comparison.