/*
 * Buzz motion system
 *
 * Keep shared timing, easing, distance, and semantic motion primitives here.
 * Features decide when motion runs; this layer defines how Buzz moves.
 */

:root {
  /* Durations: feedback → state change → composed arrival. */
  --motion-duration-instant: 120ms;
  --motion-duration-fast: 180ms;
  --motion-duration-standard: 240ms;
  --motion-duration-arrival: 500ms;

  /* Easing: direct for feedback, confident deceleration for entrances. */
  --motion-ease-standard: cubic-bezier(0.25, 1, 0.5, 1);
  --motion-ease-arrival: cubic-bezier(0.16, 1, 0.3, 1);

  /* Distances stay restrained so motion supports hierarchy without spectacle. */
  --motion-distance-arrival: 0.75rem;
  --motion-blur-arrival: 2px;
}

/* A newly-created conversational object settling into the timeline. */
.motion-enter-conversation {
  animation: motion-enter-conversation var(--motion-duration-arrival)
    var(--motion-ease-arrival) both;
}

@keyframes motion-enter-conversation {
  from {
    filter: blur(var(--motion-blur-arrival));
    opacity: 0;
    transform: translateY(var(--motion-distance-arrival));
  }

  to {
    filter: blur(0);
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .motion-enter-conversation {
    animation-duration: 1ms;
  }

  @keyframes motion-enter-conversation {
    from,
    to {
      filter: none;
      opacity: 1;
      transform: none;
    }
  }
}

/*
 * Welcome kickoff stage: the starter-team characters arrive from below with
 * a staggered entrance while the team is being set up, then the stage fades
 * out when the first agent message lands. Per-character stagger is driven by
 * the --stagger-index custom property set inline on each character.
 */
.motion-kickoff-character-enter {
  animation: motion-kickoff-character-enter var(--motion-duration-arrival)
    var(--motion-ease-arrival) both;
  animation-delay: calc(var(--stagger-index, 0) * 120ms);
}

@keyframes motion-kickoff-character-enter {
  from {
    opacity: 0;
    transform: translateY(2.5rem);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.motion-kickoff-stage-exit {
  animation: motion-kickoff-stage-exit var(--motion-duration-standard)
    var(--motion-ease-standard) both;
}

@keyframes motion-kickoff-stage-exit {
  from {
    opacity: 1;
  }

  to {
    opacity: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .motion-kickoff-character-enter,
  .motion-kickoff-stage-exit {
    animation-delay: 0ms;
    animation-duration: 1ms;
  }

  @keyframes motion-kickoff-character-enter {
    from,
    to {
      opacity: 1;
      transform: none;
    }
  }
}

/* Community switches retain the outgoing app snapshot until the target relay
   is ready, then swap atomically. Animating the snapshots creates a flash. */
::view-transition-old(root),
::view-transition-new(root) {
  animation: none;
}