/* ════════════════════════════════════════
   ZenTiles — style.css
   Gemini-inspired: dark + glass + cyan/indigo
   ════════════════════════════════════════ */

/* ── Reset & Base ─────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:            #030712;
  --surface:       rgba(255,255,255,0.05);
  --surface-hover: rgba(255,255,255,0.09);
  --border:        rgba(255,255,255,0.10);
  --border-glow:   rgba(34,211,238,0.35);

  --cyan:          #22d3ee;
  --cyan-dim:      rgba(34,211,238,0.15);
  --cyan-glow:     rgba(34,211,238,0.40);
  --indigo:        #818cf8;
  --indigo-dim:    rgba(129,140,248,0.15);
  --indigo-glow:   rgba(129,140,248,0.40);
  --violet:        #a78bfa;

  --text-primary:  #f0f4ff;
  --text-secondary:#8b9ec4;
  --text-muted:    #4b5980;

  --tile-back:     rgba(15,23,50,0.90);
  --tile-front:    rgba(8,15,40,0.95);
  --tile-matched:  rgba(34,211,238,0.12);

  --radius-sm:     8px;
  --radius-md:     14px;
  --radius-lg:     20px;
  --radius-xl:     28px;

  --font-display: 'Cinzel', serif;
  --font-body:    'Raleway', sans-serif;

  --shadow-cyan:  0 0 24px rgba(34,211,238,0.25), 0 0 60px rgba(34,211,238,0.10);
  --shadow-card:  0 8px 32px rgba(0,0,0,0.5);
}

html, body {
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

/* ── Screens ──────────────────────────── */
section {
  position: absolute;
  inset: 0;
  height: 100dvh;
  overflow: hidden;
  transition: opacity 0.45s ease, transform 0.45s ease;
}

section.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(24px);
}

/* ── Background Orbs ──────────────────── */
.home-bg-orb, .game-bg-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
  animation: orb-drift 12s ease-in-out infinite alternate;
}

.orb-1 {
  width: 420px; height: 420px;
  background: radial-gradient(circle, rgba(34,211,238,0.18), transparent 70%);
  top: -160px; right: -120px;
  animation-duration: 10s;
}
.orb-2 {
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(129,140,248,0.16), transparent 70%);
  bottom: 60px; left: -100px;
  animation-duration: 14s;
  animation-delay: -3s;
}
.orb-3 {
  width: 200px; height: 200px;
  background: radial-gradient(circle, rgba(167,139,250,0.12), transparent 70%);
  top: 55%; left: 55%;
  animation-duration: 18s;
  animation-delay: -7s;
}

.gorb-1 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(34,211,238,0.12), transparent 70%);
  top: -80px; right: -80px;
  animation-duration: 11s;
}
.gorb-2 {
  width: 250px; height: 250px;
  background: radial-gradient(circle, rgba(129,140,248,0.12), transparent 70%);
  bottom: -60px; left: -60px;
  animation-duration: 15s;
  animation-delay: -4s;
}

@keyframes orb-drift {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(30px, 20px) scale(1.08); }
}

/* ════════════════════════════════════════
   HOME SCREEN
   ════════════════════════════════════════ */
#home-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: env(safe-area-inset-top, 16px) 24px env(safe-area-inset-bottom, 16px);
}

.home-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  width: 100%;
  max-width: 380px;
  text-align: center;
}

/* Logo */
.logo-wrapper {
  position: relative;
  width: 100px;
  height: 100px;
  margin-bottom: 20px;
}
.logo-img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 24px;
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 0 20px var(--cyan-glow));
}
.logo-glow {
  position: absolute;
  inset: -10px;
  border-radius: 34px;
  background: radial-gradient(circle, var(--cyan-dim), transparent 70%);
  animation: logo-pulse 3s ease-in-out infinite;
}
@keyframes logo-pulse {
  0%, 100% { opacity: 0.5; transform: scale(1); }
  50%       { opacity: 1;   transform: scale(1.08); }
}

/* Title */
.game-title {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 8vw, 3rem);
  font-weight: 700;
  letter-spacing: 0.10em;
  background: linear-gradient(135deg, var(--cyan) 0%, var(--indigo) 60%, var(--violet) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 6px;
  text-shadow: none;
}
.game-subtitle {
  font-size: 0.82rem;
  letter-spacing: 0.20em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Divider */
.divider {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  margin-bottom: 20px;
}
.divider-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}
.divider-symbol {
  font-size: 1rem;
  opacity: 0.4;
}

/* Labels */
.choose-label {
  font-size: 0.70rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 14px;
}

/* Difficulty Buttons */
.difficulty-buttons {
  display: flex;
  gap: 14px;
  width: 100%;
  margin-bottom: 28px;
}

.diff-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  padding: 18px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  color: var(--text-primary);
  font-family: var(--font-body);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all 0.28s cubic-bezier(0.34, 1.56, 0.64, 1);
  position: relative;
  overflow: hidden;
}

.diff-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--cyan-dim), var(--indigo-dim));
  opacity: 0;
  transition: opacity 0.28s ease;
}
.diff-btn:hover::before,
.diff-btn:active::before { opacity: 1; }

.diff-btn:hover {
  border-color: var(--border-glow);
  box-shadow: var(--shadow-cyan), var(--shadow-card);
  transform: translateY(-3px) scale(1.02);
}
.diff-btn:active {
  transform: translateY(0) scale(0.97);
}

.diff-icon  { font-size: 1.8rem; z-index: 1; }
.diff-name  { font-size: 0.95rem; font-weight: 600; letter-spacing: 0.06em; z-index: 1; }
.diff-grid  {
  font-size: 0.68rem; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--cyan); z-index: 1;
}

.version-tag {
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* ════════════════════════════════════════
   GAME SCREEN
   ════════════════════════════════════════ */
#game-screen {
  display: flex;
  flex-direction: column;
  padding: env(safe-area-inset-top, 0px) 0 env(safe-area-inset-bottom, 0px);
}

/* Stats Bar */
.stats-bar {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: rgba(3,7,18,0.7);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  flex-shrink: 0;
}

.back-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--cyan);
  flex-shrink: 0;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all 0.2s ease;
}
.back-btn svg { width: 18px; height: 18px; }
.back-btn:hover {
  background: var(--cyan-dim);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-cyan);
}
.back-btn:active { transform: scale(0.92); }

.stats-group {
  display: flex;
  flex: 1;
  gap: 8px;
  justify-content: flex-end;
}

.stat-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 6px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  min-width: 60px;
}
.stat-card.accent {
  border-color: rgba(34,211,238,0.25);
  background: rgba(34,211,238,0.07);
}
.stat-label {
  font-size: 0.58rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  line-height: 1;
  margin-bottom: 2px;
}
.stat-value {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1;
}
.stat-card.accent .stat-value { color: var(--cyan); }

/* Grid Wrapper */
.grid-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px;
  overflow: hidden;
  position: relative;
  z-index: 1;
}

/* ── Grid Container ────────────────────── */
#grid-container {
  display: grid;
  gap: 8px;
  width: 100%;
  max-width: 460px;
}

#grid-container.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}
#grid-container.grid-6 {
  grid-template-columns: repeat(6, 1fr);
  gap: 5px;
  max-width: 420px;
}

/* ── Tile ─────────────────────────────── */
.tile {
  aspect-ratio: 1 / 1;
  cursor: pointer;
  perspective: 600px;
  border-radius: var(--radius-sm);
  user-select: none;
  -webkit-user-select: none;
}

.tile-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.45s cubic-bezier(0.34, 1.30, 0.64, 1);
  border-radius: inherit;
}

.tile.flipped .tile-inner  { transform: rotateY(180deg); }
.tile.matched .tile-inner  { transform: rotateY(180deg); }

.tile-face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: inherit;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

/* Back face */
.tile-back {
  background: var(--tile-back);
  border: 1px solid var(--border);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  font-size: 1rem;
  color: var(--text-muted);
  transition: border-color 0.2s ease, background 0.2s ease;
}
.tile-back::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 30%, rgba(255,255,255,0.04), transparent 60%);
  border-radius: inherit;
  pointer-events: none;
}

.tile:not(.flipped):not(.matched):hover .tile-back {
  border-color: rgba(34,211,238,0.4);
  background: rgba(34,211,238,0.07);
  box-shadow: inset 0 0 20px rgba(34,211,238,0.08);
}

/* Front face */
.tile-front {
  background: var(--tile-front);
  border: 1px solid rgba(129,140,248,0.30);
  transform: rotateY(180deg);
  font-size: clamp(1.2rem, 4.5vw, 1.8rem);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  box-shadow: inset 0 0 24px rgba(129,140,248,0.08);
}

/* Expert smaller emoji */
#grid-container.grid-6 .tile-front { font-size: clamp(0.9rem, 3.2vw, 1.3rem); }

/* Matched state */
.tile.matched .tile-back  { border-color: var(--cyan); }
.tile.matched .tile-front {
  background: var(--tile-matched);
  border-color: var(--cyan);
  box-shadow: 0 0 16px var(--cyan-glow), inset 0 0 20px var(--cyan-dim);
}

/* Shake animation for wrong match */
.tile.wrong {
  animation: shake 0.42s cubic-bezier(.36,.07,.19,.97) forwards;
}
@keyframes shake {
  10%, 90% { transform: rotate(-1deg); }
  20%, 80% { transform: rotate(2deg); }
  30%, 50%, 70% { transform: rotate(-3deg); }
  40%, 60% { transform: rotate(3deg); }
}

/* Tile reveal pop-in */
.tile {
  animation: tile-pop 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}
@keyframes tile-pop {
  from { opacity: 0; transform: scale(0.7); }
  to   { opacity: 1; transform: scale(1);   }
}

/* ════════════════════════════════════════
   WIN OVERLAY
   ════════════════════════════════════════ */
.win-overlay {
  position: absolute;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(3,7,18,0.80);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 24px;
  animation: overlay-in 0.5s ease both;
}
.win-overlay.hidden {
  display: none;
}
@keyframes overlay-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.win-card {
  background: rgba(8,15,40,0.90);
  border: 1px solid rgba(34,211,238,0.25);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  width: 100%;
  max-width: 340px;
  text-align: center;
  box-shadow: 0 0 60px rgba(34,211,238,0.12), var(--shadow-card);
  animation: card-in 0.55s cubic-bezier(0.34, 1.56, 0.64, 1) both;
  animation-delay: 0.12s;
}
@keyframes card-in {
  from { opacity: 0; transform: scale(0.8) translateY(20px); }
  to   { opacity: 1; transform: scale(1)   translateY(0);    }
}

.win-emoji {
  font-size: 3rem;
  margin-bottom: 12px;
  animation: spin-in 0.7s ease both;
  animation-delay: 0.3s;
}
@keyframes spin-in {
  from { opacity: 0; transform: rotate(-180deg) scale(0.5); }
  to   { opacity: 1; transform: rotate(0) scale(1); }
}

.win-title {
  font-family: var(--font-display);
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--cyan), var(--indigo));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
}
.win-sub {
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.win-stats {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 28px;
}
.win-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  flex: 1;
}
.win-stat.highlight {
  border-color: rgba(34,211,238,0.35);
  background: var(--cyan-dim);
}
.win-stat-label {
  font-size: 0.60rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 4px;
}
.win-stat-value {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
}
.win-stat.highlight .win-stat-value { color: var(--cyan); }

.win-actions {
  display: flex;
  gap: 10px;
}
.win-btn {
  flex: 1;
  padding: 13px 10px;
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.win-btn.primary {
  background: linear-gradient(135deg, var(--cyan), var(--indigo));
  color: #050d1e;
  font-weight: 700;
}
.win-btn.primary:hover {
  box-shadow: var(--shadow-cyan);
  transform: translateY(-2px) scale(1.02);
}
.win-btn.secondary {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text-secondary);
  backdrop-filter: blur(10px);
}
.win-btn.secondary:hover {
  border-color: var(--border-glow);
  color: var(--text-primary);
  transform: translateY(-2px);
}
.win-btn:active { transform: scale(0.96) !important; }

/* ── Responsive helpers ───────────────── */
@media (max-height: 640px) {
  .logo-wrapper     { width: 72px; height: 72px; margin-bottom: 14px; }
  .game-title        { font-size: 2rem; }
  .diff-btn          { padding: 13px 10px; }
  .diff-icon         { font-size: 1.4rem; }
}

@media (max-width: 360px) {
  #grid-container.grid-6 { gap: 4px; }
}