/* ============================================================
   PY INTERNALS — ANIMATIONS CSS
   Keyframes, transitions, entrance/exit utilities
   ============================================================ */

/* ── Page / Section Entrances ─────────────────────────────── */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.94); }
  to   { opacity: 1; transform: scale(1); }
}

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

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(20px); }
  to   { opacity: 1; transform: translateX(0); }
}

/* ── Utility Classes ──────────────────────────────────────── */
.animate-fade-up {
  animation: fadeInUp var(--dur-anim) var(--ease-out) both;
}

.animate-fade-in {
  animation: fadeIn var(--dur-slow) var(--ease-out) both;
}

.animate-scale-in {
  animation: scaleIn var(--dur-slow) var(--ease-spring) both;
}

/* Stagger delays */
.delay-1 { animation-delay: 80ms; }
.delay-2 { animation-delay: 160ms; }
.delay-3 { animation-delay: 240ms; }
.delay-4 { animation-delay: 320ms; }
.delay-5 { animation-delay: 400ms; }

/* ── Continuous / Looping ─────────────────────────────────── */
@keyframes pulse {
  0%,100% { opacity: 1; }
  50%      { opacity: 0.5; }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes bounce {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(-4px); }
}

@keyframes shimmer {
  from { background-position: -200% 0; }
  to   { background-position: 200% 0; }
}

.animate-pulse   { animation: pulse 2s ease-in-out infinite; }
.animate-spin    { animation: spin 1s linear infinite; }
.animate-bounce  { animation: bounce 1s ease-in-out infinite; }

/* ── Skeleton / Loading ───────────────────────────────────── */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--clr-surface-2) 25%,
    var(--clr-border)    50%,
    var(--clr-surface-2) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

/* ── Explanation Panel Transition ─────────────────────────── */
.explanation-enter {
  animation: fadeInUp 0.35s var(--ease-out) both;
}

.explanation-exit {
  animation: fadeIn 0.2s var(--ease-in) reverse both;
}

/* ── Code Line Highlight Pulse ────────────────────────────── */
@keyframes linePulse {
  0%   { background: rgba(26,107,92,0.35); }
  100% { background: rgba(26,107,92,0.15); }
}

.code-line.highlighting {
  animation: linePulse 0.4s var(--ease-out) forwards;
}

/* ── Reference Arrow Draw ─────────────────────────────────── */
@keyframes arrowDraw {
  from { stroke-dashoffset: 100; opacity: 0; }
  to   { stroke-dashoffset: 0;   opacity: 1; }
}

.arrow-draw {
  stroke-dasharray: 100;
  animation: arrowDraw 0.5s var(--ease-out) forwards;
}

/* ── Memory Object Appear ─────────────────────────────────── */
@keyframes memObjIn {
  0%   { opacity: 0; transform: scale(0.88) translateY(8px); }
  60%  { transform: scale(1.02) translateY(-1px); }
  100% { opacity: 1; transform: scale(1) translateY(0); }
}

@keyframes memObjOut {
  0%   { opacity: 1; transform: scale(1); }
  100% { opacity: 0; transform: scale(0.88); max-height: 0; margin: 0; padding: 0; }
}

.mem-appear { animation: memObjIn 0.45s var(--ease-spring) forwards; }
.mem-disappear { animation: memObjOut 0.3s var(--ease-in) forwards; }

/* ── Notification / Toast ─────────────────────────────────── */
@keyframes toastIn {
  from { opacity: 0; transform: translateY(12px) scale(0.96); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.toast {
  animation: toastIn 0.3s var(--ease-spring) forwards;
}

/* ── Number Counting ──────────────────────────────────────── */
@keyframes countUp {
  from { transform: translateY(6px); opacity: 0; }
  to   { transform: translateY(0);   opacity: 1; }
}
.count-change {
  animation: countUp 0.25s var(--ease-out);
}

/* ── Focus ring ───────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ── Reduced Motion ───────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}