:root {
  /* Playfulness lives here: crisp standard easing, one overshoot curve for
     affirmative interactions (button press-release, toggle, dialog entry). */
  --ease-standard: cubic-bezier(0.2, 0.8, 0.2, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-1: 90ms;
  --duration-2: 150ms;
  --duration-3: 240ms;
  --duration-4: 420ms;
  --duration-logo: 900ms;
  --transition-control: all var(--duration-2) var(--ease-standard);
  --transition-spring: transform var(--duration-3) var(--ease-spring);
  --lift-hover: translateY(-1px);
  --press-scale: scale(0.98);
  --sparkle-rest-opacity: 0.22;
  --sparkle-hover-opacity: 0.9;
  --sparkle-sketch-blur: blur(0.2px);
  --sparkle-hover-transform: rotate(4deg) scale(1.04);
  --logo-rest-transform: scale(0.96);
  --logo-hover-transform: scale(1);
}