/* ===========================================================================
   Level Up Learning — Effects: shadows, motion, blur
   Restrained, architectural. Shadows are soft + neutral (no colored glows).
   Default interaction: lift + darken on hover, slight press-down on active.
   =========================================================================== */
:root {
  /* Elevation — soft, low-spread, neutral grey */
  --shadow-xs:  0 1px 2px rgba(19,19,18,0.06);
  --shadow-sm:  0 2px 6px rgba(19,19,18,0.07);
  --shadow-md:  0 8px 24px rgba(19,19,18,0.09);
  --shadow-lg:  0 18px 48px rgba(19,19,18,0.12);
  --shadow-xl:  0 32px 80px rgba(19,19,18,0.16);
  /* Crisp ink shadow for the "stacked/architectural" card variant */
  --shadow-ink: 8px 8px 0 var(--ink);
  --shadow-mint: 8px 8px 0 var(--mint-300);

  /* Motion */
  --ease-out:    cubic-bezier(0.22, 1, 0.36, 1);   /* @kind other */
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);   /* @kind other */
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);/* @kind other */
  --dur-fast:    120ms;  /* @kind other */
  --dur-base:    200ms;  /* @kind other */
  --dur-slow:    360ms;  /* @kind other */

  /* Blur (frosted overlays / sticky nav) */
  --blur-sm: 6px;
  --blur-md: 14px;

  /* Ring */
  --ring-width: 3px;
  --ring-offset: 2px;
}