Linear progress bar, drawn as a row of glass cells. One gradient runs across the row, the cells fill one after another and the leading cell fills partially, so the value stays exact. Rising values spring the new cells up in a stagger, the leading cell breathes, and the row flashes once at 100 %. Set Indeterminate for a rolling wave of light. Variants tint the gradient, and the shared Ai state wraps the bar in the gradient aura for model-driven progress.