Gauge Meter

A semicircular speedometer gauge. A 180 degree arc carries three colored zones running from red through amber to green, tick marks sit just inside the arc, and a needle springs up from the center pivot to point at the target value while a large number below the dial counts up in sync and takes the color of the active zone.

TARGET sets the value the needle lands on across a 0 to 100 range, the ZONES array sets the colored bands and their thresholds, and LABEL and UNIT set the readout text. START_ANGLE and END_ANGLE define the sweep and R sets the dial radius. The needle and the count are driven by a single Remotion spring(), so the gauge is deterministic and comes to rest on its final value. Use it for scores, ratings, health or risk meters, and any single value measured against a scale.