:root {
  --bg: #101318;
  --panel: #191f28;
  --panel-strong: #202936;
  --cell: #0b0f14;
  --grid: rgba(255, 255, 255, 0.055);
  --text: #eef4fb;
  --muted: #9dacbd;
  --accent: #50c7f5;
  --accent-2: #f6c75a;
  --danger: #ff6b81;
  --ok: #64d68a;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background: linear-gradient(135deg, #101318, #171b22 48%, #101318);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.game-layout {
  width: min(100%, 980px);
  display: grid;
  grid-template-columns: minmax(300px, 460px) minmax(280px, 340px);
  gap: 20px;
  align-items: start;
}

.play-area,
.side-panel {
  border: 1px solid rgba(255, 255, 255, 0.11);
  border-radius: 8px;
  background: rgba(25, 31, 40, 0.92);
  box-shadow: var(--shadow);
}

.play-area {
  padding: 18px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  margin-bottom: 16px;
}

.eyebrow {
  margin: 0 0 5px;
  color: var(--accent-2);
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: 2.6rem;
  line-height: 1;
  letter-spacing: 0;
}

.state-pill {
  min-width: 88px;
  padding: 8px 11px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  color: var(--muted);
  background: var(--panel-strong);
  text-align: center;
  white-space: nowrap;
}

.state-pill.playing {
  color: #cbf7d9;
  border-color: rgba(100, 214, 138, 0.35);
}

.state-pill.ended {
  color: #ffd2da;
  border-color: rgba(255, 107, 129, 0.38);
}

.board-frame {
  position: relative;
  width: min(100%, 390px);
  margin: 0 auto;
  aspect-ratio: 1 / 2;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  background-color: var(--cell);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 10% 5%;
}

#board {
  display: block;
  width: 100%;
  height: 100%;
}

.overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  gap: 8px;
  padding: 20px;
  background: rgba(11, 15, 20, 0.72);
  text-align: center;
  transition: opacity 0.16s ease, visibility 0.16s ease;
}

.overlay.hidden {
  opacity: 0;
  visibility: hidden;
}

.overlay strong {
  font-size: 1.8rem;
}

.overlay span {
  color: var(--muted);
  line-height: 1.45;
}

.side-panel {
  padding: 18px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.stat,
.preview-box {
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  background: var(--panel-strong);
}

.stat {
  min-width: 0;
  padding: 12px 10px;
}

.stat span,
.preview-box span {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
}

.stat strong {
  display: block;
  margin-top: 6px;
  font-size: 1.7rem;
  line-height: 1;
  overflow-wrap: anywhere;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 12px;
}

.preview-box {
  padding: 12px;
}

.preview-box canvas {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 8px;
  aspect-ratio: 1 / 1;
  border-radius: 6px;
  background: #0d1219;
}

.controls {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 14px;
}

button {
  min-height: 44px;
  border: 0;
  border-radius: 8px;
  color: #071117;
  background: var(--accent);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  transition: filter 0.15s ease, transform 0.15s ease, opacity 0.15s ease;
}

button:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
}

button:active {
  transform: translateY(0);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.52;
  transform: none;
}

#pauseBtn {
  background: var(--accent-2);
}

#restartBtn {
  color: #2a0710;
  background: var(--danger);
}

.keys {
  display: grid;
  gap: 8px;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.keys div {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 7px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.keys dt,
.keys dd {
  margin: 0;
}

.keys dd {
  color: var(--text);
  text-align: right;
}

@media (max-width: 760px) {
  .app-shell {
    padding: 14px;
    align-items: start;
  }

  .game-layout {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .topbar {
    align-items: flex-start;
  }

  h1 {
    font-size: 2.15rem;
  }

  .overlay strong {
    font-size: 1.45rem;
  }

  .board-frame {
    width: min(100%, 340px);
  }
}

@media (max-width: 430px) {
  .play-area,
  .side-panel {
    padding: 14px;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr 1fr;
    gap: 7px;
  }

  .stat {
    padding: 10px 8px;
  }

  .stat strong {
    font-size: 1.25rem;
  }

  .preview-grid {
    grid-template-columns: 1fr 1fr;
    gap: 7px;
  }
}