/* ─── Animations: Card Flip, Transitions, Game States ───────────────────── */

/* ─── Card Matching Game ─────────────────────────────────────────────────── */

.match-grid {
  display: grid;
  gap: var(--space-3);
  margin: var(--space-6) auto;
  max-width: 800px;
}

.match-grid.size-10 {
  grid-template-columns: repeat(4, 1fr);
}

.match-grid.size-20 {
  grid-template-columns: repeat(5, 1fr);
}

.match-card-scene {
  perspective: 600px;
  aspect-ratio: 4/5;
}

.match-card {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  user-select: none;
}

.match-card.face-up {
  transform: rotateY(180deg);
}

.match-card.matched {
  transform: rotateY(180deg);
  cursor: default;
}

.match-card-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3);
  text-align: center;
}

/* Card back (hidden face) */
.match-card-face.back-face {
  background: var(--color-primary);
  border: 2px solid var(--color-primary-light);
  /* decorative pattern */
  background-image: repeating-linear-gradient(
    45deg,
    rgba(255,255,255,0.04) 0px,
    rgba(255,255,255,0.04) 2px,
    transparent 2px,
    transparent 10px
  );
}

.match-card-back-icon {
  font-size: 24px;
  opacity: 0.6;
}

/* Card front (revealed face) */
.match-card-face.front-face {
  transform: rotateY(180deg);
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  flex-direction: column;
  gap: var(--space-2);
  box-shadow: var(--shadow-sm);
}

.match-card-face.front-face .card-lang {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  color: var(--color-text-faint);
}

.match-card-face.front-face .card-text {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.3;
}

/* Matched state */
.match-card.matched .match-card-face.front-face {
  background: var(--color-correct-bg);
  border-color: var(--color-correct);
  animation: match-pulse 0.4s ease;
}

.match-card.matched .match-card-face.front-face .card-text {
  color: var(--color-correct);
}

@keyframes match-pulse {
  0%   { transform: rotateY(180deg) scale(1); }
  40%  { transform: rotateY(180deg) scale(1.06); }
  100% { transform: rotateY(180deg) scale(1); }
}

/* Mismatch shake */
.match-card.mismatch .match-card-face.front-face {
  border-color: var(--color-wrong);
  background: var(--color-wrong-bg);
  animation: mismatch-shake 0.4s ease;
}

@keyframes mismatch-shake {
  0%, 100% { transform: rotateY(180deg) translateX(0); }
  25%       { transform: rotateY(180deg) translateX(-4px); }
  75%       { transform: rotateY(180deg) translateX(4px); }
}

/* ─── Page Transitions ───────────────────────────────────────────────────── */

.view-enter {
  animation: view-enter 0.2s ease;
}

@keyframes view-enter {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ─── Answer Flash ───────────────────────────────────────────────────────── */

.flash-correct {
  animation: flash-correct 0.5s ease;
}

.flash-close {
  animation: flash-close 0.5s ease;
}

.flash-wrong {
  animation: flash-wrong 0.5s ease;
}

@keyframes flash-correct {
  0%   { background: var(--color-correct-bg); }
  100% { background: transparent; }
}

@keyframes flash-close {
  0%   { background: var(--color-close-bg); }
  100% { background: transparent; }
}

@keyframes flash-wrong {
  0%   { background: var(--color-wrong-bg); }
  100% { background: transparent; }
}

/* ─── Combo Pop ──────────────────────────────────────────────────────────── */

.combo-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--color-accent);
  color: white;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 700;
  animation: combo-pop 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes combo-pop {
  from { transform: scale(0.5); opacity: 0; }
  to   { transform: scale(1);   opacity: 1; }
}

/* ─── Fade Utilities ─────────────────────────────────────────────────────── */

.fade-in {
  animation: fade-in-anim 0.3s ease;
}

@keyframes fade-in-anim {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ─── Slide-in ───────────────────────────────────────────────────────────── */

.slide-up {
  animation: slide-up 0.3s ease;
}

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

/* ─── OCR Progress ───────────────────────────────────────────────────────── */

.ocr-progress-wrap {
  margin-top: var(--space-4);
}

.ocr-progress-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
  display: flex;
  justify-content: space-between;
}

/* ─── End Screen ─────────────────────────────────────────────────────────── */

.end-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
  padding: var(--space-10) var(--space-8);
  text-align: center;
  animation: slide-up 0.4s ease;
}

.end-screen-emoji {
  font-size: 64px;
  line-height: 1;
}

.end-screen-title {
  font-size: var(--text-2xl);
  font-weight: 700;
}

.end-screen-stats {
  display: flex;
  gap: var(--space-8);
  flex-wrap: wrap;
  justify-content: center;
}

.end-screen-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-1);
}

.end-screen-stat-value {
  font-size: var(--text-2xl);
  font-weight: 700;
}

.end-screen-stat-label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  font-weight: 600;
}

/* ─── Image Preview ──────────────────────────────────────────────────────── */

.image-preview-wrap {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
}

.image-preview-wrap img {
  width: 100%;
  max-height: 320px;
  object-fit: contain;
}

.image-preview-wrap .image-overlay {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  display: flex;
  gap: var(--space-2);
}

/* ─── AI Thinking ────────────────────────────────────────────────────────── */

.thinking-dots span {
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--color-primary);
  border-radius: 50%;
  margin: 0 2px;
  animation: thinking-bounce 1.2s infinite ease-in-out;
}

.thinking-dots span:nth-child(2) { animation-delay: 0.2s; }
.thinking-dots span:nth-child(3) { animation-delay: 0.4s; }

@keyframes thinking-bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.5; }
  40%           { transform: translateY(-6px); opacity: 1; }
}

/* ─── Flashcard ──────────────────────────────────────────────────────────── */

.flashcard-scene {
  perspective: 1000px;
  max-width: 480px;
  margin: 0 auto;
  cursor: pointer;
}

.flashcard {
  position: relative;
  width: 100%;
  height: 280px;
  transform-style: preserve-3d;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: var(--radius-xl);
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-8) var(--space-6);
  gap: var(--space-4);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.flashcard-face.front {
  background: var(--color-surface);
}

.flashcard-face.back {
  background: var(--color-primary-subtle);
  transform: rotateY(180deg);
}

.flashcard-word {
  font-size: var(--text-2xl);
  font-weight: 600;
  color: var(--color-text);
  text-align: center;
  line-height: 1.3;
}

.flashcard-word.font-serif {
  font-family: var(--font-serif);
  font-size: var(--text-3xl);
  font-weight: 400;
  font-style: normal;
}

.flashcard-tap-hint {
  position: absolute;
  bottom: var(--space-5);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ─── Score / result colours ─────────────────────────────────────────────── */

.score-correct { color: var(--color-correct); }
.score-wrong   { color: var(--color-wrong); }
.score-close   { color: var(--color-close); }

/* ─── Font helpers ───────────────────────────────────────────────────────── */

.font-serif { font-family: var(--font-serif); }