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

body {
  font-family: 'Nunito', sans-serif;
  background: #faf8ef;
  color: #776e65;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.6rem 1rem;
  background: linear-gradient(135deg, #ff6b35, #e85d2a);
  color: #fff; font-family: 'Nunito', sans-serif;
}
.btn-back {
  color: #fff; text-decoration: none; font-weight: 700; font-size: 1rem;
  padding: 0.3rem 0.7rem; border-radius: 8px; background: rgba(255,255,255,0.15);
}
.btn-back:hover { background: rgba(255,255,255,0.3); }
.game-title { font-size: 1.25rem; font-weight: 800; }
.stats { font-weight: 700; }

.game-container {
  flex: 1; display: flex; flex-direction: column; align-items: center;
  justify-content: center; padding: 1rem; gap: 1rem;
  max-width: 500px; margin: 0 auto; width: 100%;
}

.score-bar {
  display: flex; gap: 1rem; width: 100%; max-width: 400px;
}
.score-box {
  flex: 1; background: #bbada0; border-radius: 8px; padding: 0.5rem;
  text-align: center; color: #fff;
}
.score-label { font-size: 0.7rem; font-weight: 700; text-transform: uppercase; opacity: 0.8; }
.score-value { font-size: 1.4rem; font-weight: 800; }

.board {
  background: #bbada0; border-radius: 12px; padding: 10px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
  width: min(400px, 90vw); aspect-ratio: 1;
}

.cell {
  background: rgba(238,228,218,0.35); border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: clamp(1.2rem, 5vw, 2rem);
  aspect-ratio: 1;
  transition: transform 0.1s;
}

.cell[data-value="2"]    { background: #eee4da; color: #776e65; }
.cell[data-value="4"]    { background: #ede0c8; color: #776e65; }
.cell[data-value="8"]    { background: #f2b179; color: #f9f6f2; }
.cell[data-value="16"]   { background: #f59563; color: #f9f6f2; }
.cell[data-value="32"]   { background: #f67c5f; color: #f9f6f2; }
.cell[data-value="64"]   { background: #f65e3b; color: #f9f6f2; }
.cell[data-value="128"]  { background: #edcf72; color: #f9f6f2; font-size: clamp(1rem, 4.5vw, 1.8rem); }
.cell[data-value="256"]  { background: #edcc61; color: #f9f6f2; font-size: clamp(1rem, 4.5vw, 1.8rem); }
.cell[data-value="512"]  { background: #edc850; color: #f9f6f2; font-size: clamp(1rem, 4.5vw, 1.8rem); }
.cell[data-value="1024"] { background: #edc53f; color: #f9f6f2; font-size: clamp(0.85rem, 3.5vw, 1.5rem); }
.cell[data-value="2048"] { background: #edc22e; color: #f9f6f2; font-size: clamp(0.85rem, 3.5vw, 1.5rem); }

.cell.new { animation: appear 0.2s ease; }
.cell.merged { animation: pop 0.2s ease; }

@keyframes appear {
  0% { transform: scale(0); }
  100% { transform: scale(1); }
}
@keyframes pop {
  0% { transform: scale(1); }
  50% { transform: scale(1.15); }
  100% { transform: scale(1); }
}

.btn-orange {
  background: linear-gradient(135deg, #ff6b35, #e85d2a); color: #fff;
  padding: 0.7rem 2rem; font-size: 1rem; border-radius: 10px; border: none;
  cursor: pointer; font-family: 'Nunito', sans-serif; font-weight: 700;
  transition: transform 0.15s;
}
.btn-orange:hover { transform: translateY(-2px); }

.hint-text { font-size: 0.8rem; color: #999; text-align: center; }

.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,0.6);
  display: none; align-items: center; justify-content: center;
  z-index: 1000; padding: 1rem;
}
.modal-overlay.show { display: flex; }
.modal {
  background: #faf8ef; border-radius: 16px; padding: 2rem;
  text-align: center; max-width: 360px; width: 100%;
  box-shadow: 0 10px 40px rgba(0,0,0,0.3);
}
.modal h2 { font-size: 1.6rem; margin-bottom: 0.5rem; color: #776e65; }
.modal p { font-size: 1.1rem; margin-bottom: 1rem; color: #776e65; }

/* ===== RESPONSIVIDADE MOBILE ===== */
@media (max-width: 480px) {
  .game-container { padding: 0.5rem; gap: 0.6rem; }
  .board { padding: 6px; gap: 6px; }
  .score-bar { gap: 0.5rem; }
  .score-value { font-size: 1.1rem; }
  .score-label { font-size: 0.65rem; }
  .btn-orange { padding: 0.6rem 1.2rem; font-size: 0.9rem; }
  .hint-text { font-size: 0.72rem; }
}

/* ===== SEO GAME INFO SECTION ===== */
.game-info {
  max-width: 780px;
  margin: 1rem auto;
  padding: 1rem 1.2rem;
  background: rgba(0,0,0,0.15);
  border-radius: 12px;
  color: rgba(255,255,255,0.85);
  font-size: 0.88rem;
  line-height: 1.6;
}
.game-info h2 { font-size: 1.1rem; font-weight: 800; margin-bottom: 0.5rem; }
.game-info h3 { font-size: 0.95rem; font-weight: 700; margin: 0.8rem 0 0.3rem; }
.game-info ul { padding-left: 1.2rem; }
.game-info li { margin-bottom: 0.2rem; }