Press any card or button: ink blooms from exactly where you touched, spreads across the surface, and the control dips and springs back. Immediate feedback — and scrolling the list never fires it by accident.
Small round targets ripple too — from the exact touch point.
0 rAF at idle. Each ripple is a self-terminating one-shot animation that removes itself when it ends — there is no loop running, so the phone does zero work between taps. Under reduced-motion the ripple and press-scale are off and every control still works.