A progress/validation-fill indicator rendered as torch brazing: molten filler is drawn sideways along a hairline joint gap by capillary action, brightest at the leading front, settling into a solidified track behind it, and pooling into a fillet the instant it reaches the far end before cooling, fading, and starting a fresh joint.
npx shadcn@latest add https://design.helpmarq.com/r/braze-capillary-fill.jsonbraze-capillary-fill