An activity rings chart displays goal completion for several metrics at once using concentric radial progress arcs, in the style popularized by fitness trackers. Each ring is a partial arc with rounded end caps that starts at the top (12 o'clock) and sweeps clockwise in proportion to how close the metric is to its goal, with a distinct color per metric and a faint background track showing the full circle. It is instantly recognizable and ideal for at-a-glance comparison of progress across a small set of related goals, filling the general radial-progress gap that needle gauges (`gauge-basic`) and polar bars (`polar-bar`) do not cover.
