:root {
  --bg-top: #082f3f;
  --bg-bottom: #0a172d;
  --panel-bg: rgba(4, 21, 38, 0.72);
  --panel-border: rgba(147, 237, 255, 0.18);
  --text-primary: #ecfdff;
  --text-muted: #a7d8e5;
  --accent: #35f2cc;
  --accent-2: #f7a600;
  --danger: #ff6d6d;
  --cell-bg: rgba(7, 42, 67, 0.82);
  --cell-border: rgba(122, 224, 255, 0.28);
  --cell-hover: rgba(55, 216, 255, 0.14);
  --shadow: 0 20px 40px rgba(1, 7, 18, 0.38);
}

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

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Sora", sans-serif;
  color: var(--text-primary);
  background:
    radial-gradient(circle at 10% 20%, rgba(47, 176, 255, 0.32), transparent 45%),
    radial-gradient(circle at 90% 80%, rgba(247, 166, 0, 0.18), transparent 48%),
    linear-gradient(160deg, var(--bg-top), var(--bg-bottom));
  display: grid;
  place-items: center;
  padding: 1.25rem;
}

.app-shell {
  width: min(960px, 100%);
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 1.1rem;
  align-items: start;
}

.panel {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 1rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(7px);
}

.game-panel {
  padding: 1.15rem 1.15rem 1.25rem;
}

.game-header h1 {
  margin: 0.15rem 0 0;
  letter-spacing: 0.03em;
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  line-height: 1.1;
}

.eyebrow {
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.7rem;
  color: var(--accent);
  font-weight: 700;
}

.subtitle {
  margin: 0.4rem 0 0;
  color: var(--text-muted);
  font-size: 0.93rem;
}

.status {
  margin: 1rem 0;
  padding: 0.8rem 0.95rem;
  border-radius: 0.7rem;
  border: 1px solid rgba(146, 233, 255, 0.2);
  background: rgba(3, 23, 38, 0.7);
  min-height: 3.1rem;
  display: flex;
  align-items: center;
  font-weight: 600;
}

.board {
  width: min(540px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.55rem;
}

.board.board-disabled {
  pointer-events: none;
}

.cell {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--cell-border);
  border-radius: 0.9rem;
  background: var(--cell-bg);
  color: var(--text-primary);
  font-family: "Space Mono", monospace;
  font-size: clamp(2rem, 8vw, 3rem);
  line-height: 1;
  font-weight: 700;
  cursor: pointer;
  transition: transform 160ms ease, background-color 160ms ease, border-color 160ms ease;
}

.cell:hover,
.cell:focus-visible {
  outline: none;
  border-color: rgba(76, 236, 255, 0.72);
  background: var(--cell-hover);
  transform: translateY(-1px);
}

.cell.filled {
  cursor: default;
}

.cell.filled[data-symbol="X"] {
  color: var(--accent);
}

.cell.filled[data-symbol="O"] {
  color: var(--accent-2);
}

.cell.placed {
  animation: mark-pop 220ms ease-out;
}

.cell.win {
  border-color: rgba(53, 242, 204, 0.95);
  background: rgba(53, 242, 204, 0.18);
  animation: win-pulse 900ms ease-in-out infinite;
}

.board.shake {
  animation: board-shake 240ms ease-in-out;
}

.controls {
  margin-top: 1rem;
  display: flex;
  gap: 0.65rem;
}

.action {
  flex: 1;
  border: none;
  border-radius: 999px;
  padding: 0.72rem 1rem;
  font-family: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 140ms ease, filter 140ms ease;
}

.action:hover,
.action:focus-visible {
  outline: none;
  transform: translateY(-1px);
  filter: brightness(1.08);
}

.action.primary {
  background: linear-gradient(135deg, #2ef2c6, #09abff);
  color: #00253a;
}

.action.secondary {
  background: linear-gradient(135deg, #1b3c69, #182844);
  color: var(--text-primary);
  border: 1px solid rgba(116, 198, 255, 0.32);
}

.score-panel {
  padding: 1.05rem;
}

.score-panel h2 {
  margin: 0 0 0.8rem;
  font-size: 1rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.score-grid {
  margin: 0;
  display: grid;
  gap: 0.65rem;
}

.score-item {
  margin: 0;
  padding: 0.7rem 0.8rem;
  border-radius: 0.7rem;
  border: 1px solid rgba(127, 209, 243, 0.2);
  background: rgba(7, 33, 56, 0.8);
}

.score-item dt {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.score-item dd {
  margin: 0.35rem 0 0;
  font-size: 1.55rem;
  font-weight: 800;
  font-family: "Space Mono", monospace;
}

@keyframes mark-pop {
  0% {
    transform: scale(0.5);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

@keyframes win-pulse {
  0%,
  100% {
    box-shadow: inset 0 0 0 0 rgba(53, 242, 204, 0.18);
  }
  50% {
    box-shadow: inset 0 0 0 6px rgba(53, 242, 204, 0.33);
  }
}

@keyframes board-shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-6px);
  }
  75% {
    transform: translateX(6px);
  }
}

@media (max-width: 900px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .score-panel {
    width: min(540px, 100%);
    margin: 0 auto;
  }

  .score-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  body {
    padding: 0.75rem;
  }

  .game-panel {
    padding: 0.95rem;
  }

  .controls {
    flex-direction: column;
  }

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