This example shows a donut chart displaying a percentage value, where the foreground arc animates to its final angle using a repeating transition. The arc’s color shifts through a gradient that changes based on the input percentage, with hover effects highlighting the path by increasing its stroke width and color. Built with D3 v5 in a React framework, the visualization uses `d3.arc`, `transition.attrTween` for smooth angle interpolation, and `linearGradient` definitions for the dynamic color stops.