:root {
  --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);
  --board-bg: #0A0E14;
}

@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(255,255,255,0.9);
    --board-bg: #F0F2F5;
  }
}

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

html, body {
  height: 100%;
  height: 100dvh;
}

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

/* ── Overlay screens ── */
.overlay {
  position: fixed;
  inset: 0;
  background: var(--overlay-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 100;
  gap: 24px;
  padding: 24px;
  transition: opacity 0.3s ease;
}

.overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

/* ── Start screen ── */
#start-screen .game-title {
  font-size: 3.5rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--accent) 0%, #7C3AED 50%, #EC4899 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  text-align: center;
}

#start-screen .game-subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: center;
}

.stats-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px 28px;
  display: flex;
  gap: 32px;
  align-items: center;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}

.stat-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}

/* ── Result screen ── */
#result-screen .result-emoji {
  font-size: 4rem;
  line-height: 1;
}

#result-screen .result-title {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

#result-screen .result-title.win {
  background: linear-gradient(135deg, #10B981, #3B82F6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#result-screen .result-title.lose {
  color: var(--text-secondary);
}

#result-screen .result-subtitle {
  font-size: 0.95rem;
  color: var(--text-secondary);
  text-align: center;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--btn-bg);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease, border-color 0.15s ease;
  min-width: 180px;
  text-align: center;
}

.btn:hover {
  background: var(--btn-active);
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: #2563EB;
  border-color: #2563EB;
}

.btn-small {
  padding: 9px 18px;
  font-size: 0.85rem;
  min-width: unset;
  border-radius: 9px;
}

/* ── Game layout ── */
#game-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 480px;
  height: 100dvh;
  padding: 12px 12px 16px;
  gap: 12px;
  position: relative;
}

/* ── Header ── */
.game-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.header-title {
  font-size: 1.1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  background: linear-gradient(135deg, var(--accent), #7C3AED);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-actions {
  display: flex;
  gap: 6px;
}

/* ── Status bar ── */
.status-bar {
  width: 100%;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.turn-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
}

.stone-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  flex-shrink: 0;
  box-shadow: 0 1px 4px rgba(0,0,0,0.4);
}

.stone-dot.black {
  background: radial-gradient(circle at 35% 35%, #555, #000);
  border: 1px solid #555;
}

.stone-dot.white {
  background: radial-gradient(circle at 35% 35%, #fff, #ccc);
  border: 1px solid #aaa;
}

.status-text {
  font-size: 0.82rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.thinking-dots {
  display: inline-flex;
  gap: 3px;
  align-items: center;
}

.thinking-dots span {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
  animation: blink 1.2s infinite;
}

.thinking-dots span:nth-child(2) { animation-delay: 0.2s; }
.thinking-dots span:nth-child(3) { animation-delay: 0.4s; }

@keyframes blink {
  0%, 80%, 100% { opacity: 0.2; }
  40% { opacity: 1; }
}

/* ── Canvas wrapper ── */
.canvas-wrapper {
  flex: 1;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 0;
}

#board {
  background: var(--board-bg);
  border-radius: 12px;
  border: 1px solid var(--border);
  cursor: crosshair;
  touch-action: none;
  display: block;
  max-width: 100%;
  max-height: 100%;
}

#board.disabled {
  cursor: default;
  pointer-events: none;
}

/* ── Mini stats ── */
.mini-stats {
  display: flex;
  gap: 8px;
  width: 100%;
}

.mini-stat {
  flex: 1;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.mini-stat .val {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
}

.mini-stat .lbl {
  font-size: 0.68rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.mini-stat.wins .val { color: #10B981; }
.mini-stat.losses .val { color: var(--text-secondary); }
.mini-stat.games .val { color: var(--accent); }