/* ============================================================
   2048 — Game Styles
   ============================================================ */

/* ── Layout ── */
body {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  padding-bottom: 2rem;
}

/* Header → see .game-header in global.css */

/* ── Grid-size Tabs ── */
.size-tabs {
  display: flex;
  background: var(--surface-2);
  border-radius: 99px;
  padding: 3px;
  gap: 2px;
  border: 1px solid var(--border);
  flex-shrink: 0;
}

.size-tab {
  padding: 0.28em 0.75em;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: all 200ms ease;
  white-space: nowrap;
}

.size-tab:hover:not(.active) {
  color: var(--text);
}

.size-tab.active {
  background: rgba(129, 140, 248, 0.2);
  color: var(--accent);
}

/* ── Stats Bar ── */
.stats-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  width: 100%;
  max-width: 520px;
  padding: 0.6rem 1rem;
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.6rem;
}

.stat-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.05rem;
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.stat-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
  transition: color 200ms ease;
}

.stat-value.flash-score {
  animation: score-flash 400ms ease;
}

@keyframes score-flash {
  0%   { transform: scale(1.3); color: var(--accent); }
  100% { transform: scale(1); color: var(--text); }
}

.stat-divider {
  width: 1px;
  height: 2rem;
  background: var(--border);
  flex-shrink: 0;
}

/* ── Game Container ── */
.game-container {
  width: 100%;
  max-width: 520px;
  padding: 0 0.75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.85rem;
}

/* ── Board Wrapper ── */
.board-wrapper {
  width: 100%;
  display: flex;
  justify-content: center;
  position: relative;
}

/* ── Board ── */
.board {
  position: relative;
  background: var(--surface-2);
  border-radius: var(--radius-lg);
  padding: 8px;
  box-shadow: var(--shadow-md);
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

/* Dynamic size set by JS via CSS vars */
.board-grid {
  display: grid;
  gap: 8px;
  position: relative;
  z-index: 1;
}

/* ── Placeholder Cells ── */
.cell-placeholder {
  background: var(--surface-3);
  border-radius: var(--radius-md);
  opacity: 0.6;
}

/* ── Tile Layer ── */
.tile-layer {
  position: absolute;
  inset: 8px;
  pointer-events: none;
  z-index: 2;
}

/* ── Tiles ── */
.tile {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-weight: 700;
  transition: left 100ms ease, top 100ms ease;
  will-change: transform, left, top;
  z-index: 2;
}

/* Tile value colors — light theme */
.tile[data-value="2"]    { background: #eee4da; color: #776e65; }
.tile[data-value="4"]    { background: #ede0c8; color: #776e65; }
.tile[data-value="8"]    { background: #f2b179; color: #f9f6f2; }
.tile[data-value="16"]   { background: #f59563; color: #f9f6f2; }
.tile[data-value="32"]   { background: #f67c5f; color: #f9f6f2; }
.tile[data-value="64"]   { background: #f65e3b; color: #f9f6f2; }
.tile[data-value="128"]  { background: #edcf72; color: #f9f6f2; }
.tile[data-value="256"]  { background: #edcc61; color: #f9f6f2; }
.tile[data-value="512"]  { background: #edc850; color: #f9f6f2; }
.tile[data-value="1024"] { background: #edc53f; color: #f9f6f2; font-size: clamp(0.9rem, 3.5vw, 1.35rem); }
.tile[data-value="2048"] { background: #edc22e; color: #f9f6f2; font-size: clamp(0.85rem, 3vw, 1.2rem); }
.tile[data-value="4096"] { background: #3c3a32; color: #f9f6f2; font-size: clamp(0.8rem, 2.8vw, 1.1rem); }
.tile[data-value="8192"] { background: #121212; color: #f9f6f2; font-size: clamp(0.75rem, 2.5vw, 1rem); }

/* Tile appear animation */
@keyframes tile-appear {
  0%   { transform: scale(0); }
  70%  { transform: scale(1.1); }
  100% { transform: scale(1); }
}

/* Tile merge pop animation */
@keyframes tile-merge {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.18); }
  100% { transform: scale(1); }
}

.tile-new {
  animation: tile-appear 180ms cubic-bezier(0.34, 1.56, 0.64, 1) both;
}

.tile-merged {
  animation: tile-merge 180ms cubic-bezier(0.34, 1.56, 0.64, 1) both;
  z-index: 3;
}

/* ── Action Row ── */
.action-row {
  display: flex;
  gap: 0.75rem;
  width: 100%;
  justify-content: center;
}

.action-btn {
  flex: 1;
  max-width: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.6rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  -webkit-tap-highlight-color: transparent;
}

.action-btn:hover:not(:disabled) {
  background: var(--surface-2);
  border-color: var(--border-strong);
  color: var(--text);
}

.action-btn:active:not(:disabled) {
  transform: scale(0.96);
}

.action-btn.btn-primary-style {
  background: var(--accent-dark);
  border-color: var(--accent);
  color: #fff;
}

.action-btn.btn-primary-style:hover:not(:disabled) {
  background: var(--accent);
  box-shadow: 0 0 16px var(--accent-glow);
  color: #fff;
}

/* ── Hint text ── */
.hint-text {
  font-size: 0.82rem;
  color: var(--text-dim);
  text-align: center;
  padding: 0 1rem;
}

/* ── Board Overlays (Win / Game Over) ── */
.board-overlay {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  z-index: 10;
  opacity: 0;
  pointer-events: none;
  transition: opacity 300ms ease;
  padding: 1.5rem;
  text-align: center;
}

.board-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.overlay-win {
  background: rgba(240, 192, 64, 0.88);
  backdrop-filter: blur(2px);
}

.overlay-gameover {
  background: rgba(13, 13, 20, 0.88);
  backdrop-filter: blur(2px);
}

.overlay-title {
  font-size: clamp(1.3rem, 5vw, 1.8rem);
  font-weight: 800;
  color: #fff;
  text-shadow: 0 2px 8px rgba(0,0,0,0.3);
  line-height: 1.2;
}

.overlay-win .overlay-title {
  color: #1a1a1a;
  text-shadow: none;
}

.overlay-score {
  font-size: 1rem;
  font-weight: 600;
  color: rgba(255,255,255,0.85);
}

.overlay-win .overlay-score {
  color: rgba(26, 26, 26, 0.75);
}

.overlay-actions {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 0.25rem;
}

.overlay-btn {
  padding: 0.5em 1.1em;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  -webkit-tap-highlight-color: transparent;
}

.overlay-btn-primary {
  background: var(--accent-dark);
  color: #fff;
  border-color: var(--accent);
}

.overlay-btn-primary:hover {
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent-glow);
}

.overlay-btn-secondary {
  background: rgba(255,255,255,0.15);
  color: #fff;
  border-color: rgba(255,255,255,0.3);
}

.overlay-btn-secondary:hover {
  background: rgba(255,255,255,0.25);
}

.overlay-win .overlay-btn-primary {
  background: #1a1a1a;
  color: #f0c040;
  border-color: #1a1a1a;
}

.overlay-win .overlay-btn-primary:hover {
  background: #333;
}

.overlay-win .overlay-btn-secondary {
  background: rgba(26,26,26,0.15);
  color: #1a1a1a;
  border-color: rgba(26,26,26,0.3);
}

.overlay-win .overlay-btn-secondary:hover {
  background: rgba(26,26,26,0.25);
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .game-header {
    padding: 0.75rem 0.75rem 0.5rem;
  }

  .game-title {
    font-size: 1.05rem;
  }

  .size-tab {
    padding: 0.25em 0.5em;
    font-size: 0.72rem;
  }

  .game-container {
    padding: 0 0.5rem;
    gap: 0.65rem;
  }

  .action-btn {
    padding: 0.5rem 0.6rem;
    font-size: 0.82rem;
  }
}

@media (max-width: 360px) {
  .game-header {
    flex-wrap: wrap;
    justify-content: center;
  }

  .game-title {
    order: -1;
    width: 100%;
    text-align: center;
  }
}