/* ============================================================
   animations.css: keyframes, transition utilities, motion primitives
   ============================================================ */

/* ── Entrances ──────────────────────────────────────────────── */
@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fade-in-down {
  from { opacity: 0; transform: translateY(-12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes scale-in {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

@keyframes slide-in-right {
  from { opacity: 0; transform: translateX(20px); }
  to { opacity: 1; transform: translateX(0); }
}

.animate-fade-in { animation: fade-in var(--ease-base) both; }
.animate-fade-in-up { animation: fade-in-up var(--ease-slow) both; }
.animate-scale-in { animation: scale-in var(--ease-bounce) both; }
.animate-slide-in-right { animation: slide-in-right var(--ease-slow) both; }

/* Staggered children */
.stagger > * { animation: fade-in-up var(--ease-slow) both; }
.stagger > *:nth-child(1) { animation-delay: 0ms; }
.stagger > *:nth-child(2) { animation-delay: 60ms; }
.stagger > *:nth-child(3) { animation-delay: 120ms; }
.stagger > *:nth-child(4) { animation-delay: 180ms; }
.stagger > *:nth-child(5) { animation-delay: 240ms; }
.stagger > *:nth-child(6) { animation-delay: 300ms; }
.stagger > *:nth-child(7) { animation-delay: 360ms; }
.stagger > *:nth-child(8) { animation-delay: 420ms; }

/* ── Flow / data movement (used by architecture diagrams) ──── */
@keyframes flow-dash {
  to { stroke-dashoffset: -20; }
}
.flow-line {
  stroke-dasharray: 6 6;
  animation: flow-dash 1s linear infinite;
}
.flow-line.paused { animation-play-state: paused; }

@keyframes packet-travel {
  from { offset-distance: 0%; }
  to { offset-distance: 100%; }
}

@keyframes glow-pulse {
  0%, 100% { filter: drop-shadow(0 0 2px var(--airflow-glow)); }
  50% { filter: drop-shadow(0 0 8px var(--airflow-glow)); }
}
.glow-pulse { animation: glow-pulse 2s ease-in-out infinite; }

/* ── Node activation (state machine, arch nodes) ───────────── */
@keyframes node-activate {
  0% { transform: scale(1); }
  50% { transform: scale(1.08); }
  100% { transform: scale(1); }
}
.node-activate { animation: node-activate var(--ease-bounce); }

@keyframes ring-ping {
  0% { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(2.2); opacity: 0; }
}
.ring-ping { animation: ring-ping 1.2s ease-out infinite; }

/* ── Spinner ────────────────────────────────────────────────── */
@keyframes spin { to { transform: rotate(360deg); } }
.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--bg-4);
  border-top-color: var(--airflow);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

/* ── Progress bar (animation timeline) ──────────────────────── */
@keyframes progress-indeterminate {
  0% { left: -40%; }
  100% { left: 100%; }
}

/* ── Typewriter reveal for code ─────────────────────────────── */
@keyframes blink-caret {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}
.caret::after {
  content: '';
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--airflow);
  vertical-align: text-bottom;
  animation: blink-caret 1s step-end infinite;
}

/* ── Reduced motion ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .flow-line { stroke-dasharray: none; }
}