/* ═══════════════════════════════════════════════════════════════════
   Mahjong Solitaire — CSS
   Mobile-first. Tile styles are self-contained (no external cards.css).
   ═══════════════════════════════════════════════════════════════════ */

/* ─── DESIGN TOKENS ─── */
:root {
  /* Palette */
  --bg-primary:    #0D1117;
  --bg-secondary:  #161B22;
  --bg-tertiary:   #21262D;
  --text-primary:  #F0F6FC;
  --text-secondary:#8B949E;
  --text-muted:    #484F58;
  --accent:        #3B82F6;
  --border:        #30363D;
  --btn-bg:        #21262D;
  --btn-active:    #30363D;
  --overlay-bg:    rgba(0, 0, 0, 0.85);

  /* Tile dimensions — responsive via media queries */
  --tile-w: 38px;
  --tile-h: 50px;
  --tile-fs: 14px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-primary:    #FFFFFF;
    --bg-secondary:  #F6F8FA;
    --bg-tertiary:   #E9ECF0;
    --text-primary:  #1B1E28;
    --text-secondary:#57606A;
    --text-muted:    #8C959F;
    --accent:        #3182F6;
    --border:        #D0D7DE;
    --btn-bg:        #E9ECF0;
    --btn-active:    #D0D7DE;
    --overlay-bg:    rgba(255, 255, 255, 0.92);
  }
}

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

html {
  height: 100%;
  font-size: 16px;
  touch-action: manipulation;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Pretendard', 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
  user-select: none;
  -webkit-user-select: none;
}

/* ─── APP SHELL ─── */
#app {
  width: 100%;
  max-width: 480px;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* ═══════════════════════════════════════════════════════════════════
   OVERLAY SCREENS (start, win)
   ═══════════════════════════════════════════════════════════════════ */
.screen {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--overlay-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 200;
  padding: 28px 24px;
  gap: 28px;
  transition: opacity 0.3s ease;
  opacity: 0;
  pointer-events: none;
}

.screen.active {
  opacity: 1;
  pointer-events: auto;
}

#game-screen {
  position: relative;
  display: none;
  flex-direction: column;
  width: 100%;
  flex: 1;
  min-height: 0;
}

#game-screen.active {
  display: flex;
}

/* ── Start screen ── */
#start-screen {
  gap: 36px;
}

.title-wrap {
  text-align: center;
}

.game-logo-css {
  font-size: 3rem;
  margin-bottom: 8px;
  animation: float 2.4s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-6px); }
}

.screen-title {
  font-size: clamp(2.6rem, 14vw, 4.5rem);
  font-weight: 800;
  letter-spacing: 0.1em;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent) 0%, #a78bfa 55%, #f472b6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.screen-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

/* ── Start preview tiles ── */
.start-tiles-preview {
  display: flex;
  gap: 10px;
  align-items: center;
  justify-content: center;
}

.preview-tile {
  width: 48px;
  height: 60px;
  background: #f8f8f0;
  border: 2px solid #d0d0c8;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
  color: #222;
  box-shadow: 0 3px 0 #ccc, 0 4px 8px rgba(0,0,0,0.3);
  cursor: default;
  user-select: none;
}

.preview-tile.red   { color: #dc2626; }
.preview-tile.green { color: #16a34a; }
.preview-tile.gold  { color: #b45309; }

/* Start button */
.start-btn {
  width: 100%;
  max-width: 300px;
  padding: 16px;
  border: none;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), #8B5CF6);
  color: #ffffff;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.35);
  transition: transform 0.15s ease, opacity 0.15s ease;
}

.start-btn:active {
  transform: scale(0.97);
  opacity: 0.9;
}

/* ── Win screen ── */
#win-screen {
  gap: 28px;
}

.win-icon {
  font-size: 4rem;
  animation: winBounce 0.6s ease infinite alternate;
}

@keyframes winBounce {
  from { transform: translateY(0) rotate(-5deg); }
  to   { transform: translateY(-10px) rotate(5deg); }
}

.win-title {
  font-size: 2rem;
  font-weight: 800;
  text-align: center;
  background: linear-gradient(135deg, #FFD700, #FF8C00);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.win-stats {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  max-width: 300px;
}

.stat-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 11px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.stat-value {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.win-actions {
  display: flex;
  gap: 10px;
  width: 100%;
  max-width: 300px;
}

.btn-primary {
  flex: 1;
  padding: 13px;
  border: none;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), #8B5CF6);
  color: #ffffff;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.btn-primary:active {
  opacity: 0.85;
  transform: scale(0.97);
}

/* ═══════════════════════════════════════════════════════════════════
   GAME HEADER
   ═══════════════════════════════════════════════════════════════════ */
#game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px 10px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-title {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  background: linear-gradient(135deg, var(--accent), #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}

.icon-btn {
  width: 36px;
  height: 36px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  background: var(--btn-bg);
  color: var(--text-secondary);
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background 0.15s ease, color 0.15s ease;
}

.icon-btn:hover {
  background: var(--btn-active);
  color: var(--text-primary);
}

.icon-btn:active {
  transform: scale(0.93);
}

/* ═══════════════════════════════════════════════════════════════════
   STATS BAR
   ═══════════════════════════════════════════════════════════════════ */
.stats-bar {
  display: flex;
  gap: 8px;
  padding: 10px 16px;
  flex-shrink: 0;
}

.stat-chip {
  flex: 1;
  padding: 8px 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-align: center;
}

.stat-chip-label {
  font-size: 0.64rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 2px;
}

.stat-chip-value {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.03em;
}

/* ═══════════════════════════════════════════════════════════════════
   GAME AREA
   ═══════════════════════════════════════════════════════════════════ */
#game-area {
  flex: 1;
  overflow: auto;
  background: linear-gradient(160deg, #0e2a1a 0%, #0b1e12 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
  min-height: 0;
  position: relative;
}

@media (prefers-color-scheme: light) {
  #game-area {
    background: linear-gradient(160deg, #2d7a4e 0%, #1f5e37 100%);
  }
}

/* ─── BOARD ─── */
#board {
  position: relative;
  /* width/height set by JS */
}

/* ═══════════════════════════════════════════════════════════════════
   MAHJONG TILES
   ═══════════════════════════════════════════════════════════════════ */
.mj-tile {
  position: absolute;
  width: var(--tile-w, 38px);
  height: var(--tile-h, 50px);
  background: #f0ece0;
  border: 1.5px solid #c0b898;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--tile-fs, 14px);
  font-weight: 700;
  color: #222;
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  box-shadow:
    2px 3px 0 #a09070,
    0 4px 8px rgba(0,0,0,0.4);
  transition: transform 0.1s, box-shadow 0.1s, filter 0.15s;
  line-height: 1.1;
  text-align: center;
  padding: 2px;
}

/* Tile colors by suit */
.mj-tile.color-red    { color: #dc2626; }
.mj-tile.color-green  { color: #16a34a; }
.mj-tile.color-blue   { color: #2563eb; }
.mj-tile.color-crimson{ color: #991b1b; }
.mj-tile.color-forest { color: #065f46; }
.mj-tile.color-gray   { color: #6b7280; }
.mj-tile.color-gold   { color: #92400e; }
.mj-tile.color-dark   { color: #1e293b; }

/* Higher layers — brighter/raised appearance */
.mj-tile.layer-1 { background: #f5f1e5; }
.mj-tile.layer-2 { background: #faf6ea; }
.mj-tile.layer-3 { background: #fff9f0; }
.mj-tile.layer-4 { background: #fffdf5; }

/* Free tile — hover */
.mj-tile.free:hover {
  transform: translateY(-2px);
  box-shadow: 3px 5px 0 #a09070, 0 6px 12px rgba(0,0,0,0.5);
  background: #fffef8;
  z-index: 200 !important;
}

/* Selected tile */
.mj-tile.selected {
  background: #dbeafe;
  border-color: #3b82f6;
  box-shadow: 2px 3px 0 #1d4ed8, 0 0 0 2px rgba(59,130,246,0.4), 0 4px 12px rgba(59,130,246,0.4);
  transform: translateY(-2px);
  z-index: 300 !important;
}

/* Blocked tile */
.mj-tile.blocked {
  cursor: default;
  opacity: 0.8;
  filter: brightness(0.88);
}

.mj-tile.blocked:hover {
  transform: none;
  box-shadow: 2px 3px 0 #a09070, 0 4px 8px rgba(0,0,0,0.4);
  background: #f0ece0;
}

/* Hint tiles */
.mj-tile.hint-a {
  animation: hint-pulse-a 0.7s ease-in-out 2;
}

.mj-tile.hint-b {
  animation: hint-pulse-b 0.7s ease-in-out 2 0.15s;
}

@keyframes hint-pulse-a {
  0%,100% { box-shadow: 2px 3px 0 #a09070, 0 4px 8px rgba(0,0,0,0.4); }
  50% { box-shadow: 2px 3px 0 #a09070, 0 0 0 4px rgba(245,158,11,0.6), 0 4px 16px rgba(245,158,11,0.5); background: #fef3c7; }
}

@keyframes hint-pulse-b {
  0%,100% { box-shadow: 2px 3px 0 #a09070, 0 4px 8px rgba(0,0,0,0.4); }
  50% { box-shadow: 2px 3px 0 #a09070, 0 0 0 4px rgba(34,197,94,0.6), 0 4px 16px rgba(34,197,94,0.5); background: #dcfce7; }
}

/* Removed tile — invisible */
.mj-tile.removed {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

/* ═══════════════════════════════════════════════════════════════════
   NO MOVES MESSAGE
   ═══════════════════════════════════════════════════════════════════ */
#no-moves-msg {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0,0,0,0.9);
  color: #fff;
  padding: 20px 28px;
  border-radius: 12px;
  text-align: center;
  z-index: 500;
  display: none;
}

#no-moves-msg h3 {
  margin-bottom: 12px;
  font-size: 16px;
}

#no-moves-msg button {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  font-weight: 600;
}

/* ═══════════════════════════════════════════════════════════════════
   BOTTOM CONTROLS
   ═══════════════════════════════════════════════════════════════════ */
#bottom-controls {
  display: flex;
  gap: 6px;
  padding: 10px 16px calc(14px + env(safe-area-inset-bottom, 0px));
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.ctrl-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 8px 4px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  background: var(--btn-bg);
  color: var(--text-secondary);
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, transform 0.1s ease;
  -webkit-tap-highlight-color: transparent;
}

.ctrl-btn:hover {
  background: var(--btn-active);
  color: var(--text-primary);
}

.ctrl-btn:active {
  transform: scale(0.94);
}

.ctrl-btn:disabled {
  opacity: 0.38;
  pointer-events: none;
}

.ctrl-btn-icon {
  font-size: 1.1rem;
  line-height: 1;
}

.ctrl-btn-label {
  font-size: 0.58rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* ═══════════════════════════════════════════════════════════════════
   SCROLLBAR
   ═══════════════════════════════════════════════════════════════════ */
::-webkit-scrollbar {
  width: 4px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

/* ═══════════════════════════════════════════════════════════════════
   RESPONSIVE TILE SIZING
   ═══════════════════════════════════════════════════════════════════ */
@media (max-width: 400px) {
  :root {
    --tile-w: 32px;
    --tile-h: 42px;
    --tile-fs: 11px;
  }
}

@media (min-width: 401px) {
  :root {
    --tile-w: 36px;
    --tile-h: 48px;
    --tile-fs: 13px;
  }
}

@media (min-width: 480px) {
  :root {
    --tile-w: 40px;
    --tile-h: 52px;
    --tile-fs: 15px;
  }
}

/* ═══════════════════════════════════════════════════════════════════
   MISC
   ═══════════════════════════════════════════════════════════════════ */
.mj-tile {
  -webkit-touch-callout: none;
}

@media (prefers-reduced-motion: reduce) {
  .win-icon             { animation: none; }
  .game-logo-css        { animation: none; }
  .mj-tile.hint-a,
  .mj-tile.hint-b       { animation: none; }
  @keyframes winBounce  { from {} to {} }
}