/* ════════════════════════════════════════════════════════════
   2048 GAME  ·  style.css
   Professional styling with animations and responsive design
   ════════════════════════════════════════════════════════════ */

/* ── CSS VARIABLES ───────────────────────────────────────────– */
:root[data-theme="dark"] {
  --bg-primary: #121212;
  --bg-secondary: #1e1e1e;
  --bg-tertiary: #2a2a2a;
  --txt: #f9f6f2;
  --txt-dim: #9f9f9f;
  --clr-primary: #8f7a66;
  --clr-accent: #f67c5f;
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}

:root[data-theme="light"] {
  --bg-primary: #faf8f3;
  --bg-secondary: #f0ebe5;
  --bg-tertiary: #e8dcc8;
  --txt: #776e65;
  --txt-dim: #b0a898;
  --clr-primary: #8f7a66;
  --clr-accent: #f67c5f;
  --glass-bg: rgba(0, 0, 0, 0.02);
  --glass-border: rgba(0, 0, 0, 0.08);
  --shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-primary);
  color: var(--txt);
  transition: background-color 0.3s ease, color 0.3s ease;
}

body {
  min-height: 100vh;
  background: var(--bg-primary);
  overflow-x: hidden;
}

/* ── LAYOUT ──────────────────────────────────────────────────– */
.game-layout-wrapper {
  display: grid;
  grid-template-columns: 300px 1fr 300px;
  gap: 20px;
  padding: 20px;
  min-height: 100vh;
  max-width: 1400px;
  margin: 0 auto;
}

.ad-sidebar {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 20px 0;
}

.ad-container {
  width: 100%;
  max-width: 300px;
}

.game-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* ── HEADER ──────────────────────────────────────────────────– */
.game-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  backdrop-filter: blur(10px);
}

.back-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  background: transparent;
  border: 1px solid var(--glass-border);
  border-radius: 6px;
  color: var(--txt);
  cursor: pointer;
  font-size: 0.9em;
  font-weight: 500;
  transition: all 0.2s ease;
}

.back-btn:hover {
  background: var(--glass-bg);
  border-color: var(--clr-primary);
}

.back-btn svg {
  width: 18px;
  height: 18px;
}

.game-title {
  font-size: 2.5em;
  font-weight: 900;
  letter-spacing: 2px;
  text-align: center;
  flex: 1;
}

.header-controls {
  display: flex;
  gap: 8px;
}

.icon-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--glass-border);
  border-radius: 8px;
  color: var(--txt);
  cursor: pointer;
  transition: all 0.2s ease;
}

.icon-btn:hover {
  background: var(--glass-bg);
  border-color: var(--clr-primary);
}

.icon-btn svg {
  width: 20px;
  height: 20px;
}

/* ── GLASS CARD ──────────────────────────────────────────────– */
.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  backdrop-filter: blur(10px);
  padding: 16px;
}

/* ── SCORE PANEL ─────────────────────────────────────────────– */
.score-panel {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
  align-items: center;
}

.score-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
  text-align: center;
}

.score-label {
  font-size: 0.75em;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--txt-dim);
}

.score-value {
  font-size: 2em;
  font-weight: 900;
  color: var(--clr-accent);
}

/* ── BUTTONS ─────────────────────────────────────────────────– */
.primary-btn,
.secondary-btn {
  padding: 12px 20px;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.95em;
}

.primary-btn {
  background: var(--clr-primary);
  color: var(--txt);
}

.primary-btn:hover {
  background: var(--clr-accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(246, 124, 95, 0.3);
}

.secondary-btn {
  background: transparent;
  border: 1px solid var(--clr-primary);
  color: var(--txt);
}

.secondary-btn:hover {
  background: var(--clr-primary);
  color: var(--bg-primary);
}

/* ── STATUS BAR ──────────────────────────────────────────────– */
.status-bar {
  text-align: center;
  padding: 12px;
  font-size: 1.2em;
  font-weight: 600;
  color: var(--clr-accent);
}

/* ── GAME BOARD ──────────────────────────────────────────────– */
.game-board-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 400px;
}

.game-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(4, 1fr);
  gap: 12px;
  padding: 16px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  backdrop-filter: blur(10px);
  aspect-ratio: 1;
  width: 100%;
  max-width: 400px;
}

.game-cell {
  background: rgba(0, 0, 0, 0.1);
  border-radius: 8px;
}

/* ── TILES ───────────────────────────────────────────────────– */
.tile {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-weight: 900;
  user-select: none;
  font-size: 2.5em;
  transition: all 0.1s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.tile.moving {
  transition: none;
}

.tile.new-tile {
  animation: tileAppear 0.1s ease-out;
}

.tile.merge-pop {
  animation: mergePop 0.1s ease-out;
}

@keyframes tileAppear {
  from {
    transform: scale(0.8);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes mergePop {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
  100% {
    transform: scale(1);
  }
}

/* ── CONTROL PANEL ───────────────────────────────────────────– */
.control-panel {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.control-panel button {
  flex: 1;
  max-width: 150px;
}

/* ── OVERLAYS ────────────────────────────────────────────────– */
.overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s ease;
}

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

.overlay-content {
  background: var(--bg-primary);
  padding: 40px;
  border-radius: 16px;
  text-align: center;
  max-width: 400px;
  box-shadow: var(--shadow);
  animation: slideUp 0.3s ease;
}

.overlay-content h2 {
  font-size: 2em;
  margin-bottom: 12px;
  color: var(--clr-accent);
}

.overlay-content p {
  font-size: 1.2em;
  margin-bottom: 24px;
  color: var(--txt-dim);
}

.overlay-content button {
  width: 100%;
  margin-top: 8px;
}

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

/* ── UTILITIES ───────────────────────────────────────────────– */
.hidden {
  display: none !important;
}

/* ── RESPONSIVE ──────────────────────────────────────────────– */
@media (max-width: 1024px) {
  .game-layout-wrapper {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .ad-sidebar {
    display: none;
  }

  .game-board {
    max-width: 360px;
    gap: 10px;
    padding: 12px;
  }

  .tile {
    font-size: 2em;
  }
}

@media (max-width: 768px) {
  .game-title {
    font-size: 1.8em;
    letter-spacing: 1px;
  }

  .score-panel {
    grid-template-columns: 1fr 1fr;
  }

  .primary-btn {
    grid-column: 1 / -1;
  }

  .game-board {
    max-width: 280px;
    gap: 8px;
    padding: 10px;
  }

  .tile {
    font-size: 1.5em;
  }

  .control-panel {
    flex-wrap: wrap;
  }

  .control-panel button {
    flex: 0 0 calc(50% - 6px);
  }
}

@media (max-width: 480px) {
  .game-layout-wrapper {
    padding: 12px;
    gap: 12px;
  }

  .game-header {
    padding: 12px;
  }

  .back-btn {
    padding: 6px 10px;
    font-size: 0.8em;
  }

  .back-btn svg {
    width: 16px;
    height: 16px;
  }

  .game-title {
    font-size: 1.5em;
    letter-spacing: 0px;
  }

  .score-value {
    font-size: 1.5em;
  }

  .game-board {
    max-width: 100%;
    gap: 6px;
    padding: 8px;
  }

  .tile {
    font-size: 1.2em;
    border-radius: 6px;
  }

  .game-cell {
    border-radius: 6px;
  }

  .glass-card {
    padding: 12px;
    border-radius: 8px;
  }

  .overlay-content {
    padding: 24px;
    border-radius: 12px;
    max-width: 90%;
  }

  .overlay-content h2 {
    font-size: 1.5em;
  }

  .overlay-content p {
    font-size: 1em;
  }
}