:root {
  --board-color: #DEB887;
  --board-dark: #C19A49;
  --line-color: #5C3D1E;
  --bg-color: #2c1810;
  --accent: #FFD700;
  --win-color: #FF4444;
  --text-color: #f0e6d2;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  background: linear-gradient(135deg, #1a0f0a 0%, #3d2216 50%, #1a0f0a 100%);
  min-height: 100vh;
  display: flex; flex-direction: column; align-items: center;
  font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
  color: var(--text-color); overflow-x: hidden;
}
h1 { margin: 16px 0 8px; font-size: 2em; text-shadow: 2px 2px 4px rgba(0,0,0,0.5); letter-spacing: 4px; }
h1 span.black { color: #1a1a1a; text-shadow: 0 0 4px #555; }
h1 span.white { color: #f5f5f5; text-shadow: 0 0 4px #aaa; }

/* 按钮 */
.btn {
  padding: 8px 18px; border: 2px solid var(--accent);
  background: rgba(255,215,0,0.1); color: var(--accent);
  font-size: 1em; border-radius: 6px; cursor: pointer;
  transition: all 0.2s; font-family: inherit; white-space: nowrap;
}
.btn:hover { background: rgba(255,215,0,0.25); }
.btn.active { background: var(--accent); color: #1a0f0a; font-weight: bold; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn.large { padding: 14px 36px; font-size: 1.2em; }

/* 控制栏 */
.controls {
  display: flex; gap: 10px; flex-wrap: wrap;
  justify-content: center; align-items: center;
  margin: 8px 0; padding: 0 10px;
}

/* 状态栏 */
.status-bar {
  margin: 8px 0; font-size: 1.1em; min-height: 1.6em;
  text-align: center; display: flex; align-items: center; gap: 8px; justify-content: center;
}
.stone-icon {
  display: inline-block; width: 20px; height: 20px;
  border-radius: 50%; vertical-align: middle; border: 1px solid #888;
}
.stone-icon.black { background: radial-gradient(circle at 35% 35%, #555, #1a1a1a); }
.stone-icon.white { background: radial-gradient(circle at 35% 35%, #fff, #ccc); }

#thinking, .thinking { color: var(--accent); animation: blink 1s infinite; }
@keyframes blink { 50% { opacity: 0.4; } }

/* 棋盘 */
#canvas-wrap { position: relative; margin: 0 auto 16px; }
canvas {
  display: block; border-radius: 8px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.6), 0 0 0 3px #8B6914;
  cursor: pointer;
}

/* 计分板 */
.score-board { display: flex; gap: 24px; font-size: 0.95em; margin-bottom: 4px; }
.score-board span { color: #bbb; }
.score-board b { color: var(--accent); }

/* 返回按钮 */
.back-btn {
  position: absolute; left: 16px; top: 16px;
  color: var(--accent); text-decoration: none; font-size: 1em;
  border: 1px solid rgba(255,215,0,0.3); padding: 6px 14px;
  border-radius: 6px; transition: all 0.2s;
}
.back-btn:hover { background: rgba(255,215,0,0.15); }

/* 弹窗 */
.overlay {
  display: none; position: fixed; inset: 0;
  background: rgba(0,0,0,0.7); z-index: 100;
  justify-content: center; align-items: center;
}
.overlay.show { display: flex; }
.overlay-box {
  background: linear-gradient(135deg, #3d2216, #2c1810);
  border: 3px solid var(--accent); border-radius: 16px;
  padding: 40px 60px; text-align: center;
  box-shadow: 0 0 60px rgba(255,215,0,0.3);
  animation: popIn 0.4s ease-out;
}
@keyframes popIn { from { transform: scale(0.5); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.overlay-box h2 { font-size: 2em; margin-bottom: 16px; color: var(--accent); }
.overlay-box .btn { font-size: 1.1em; margin-top: 10px; }

/* 金币显示 */
.coin-display {
  position: absolute; right: 16px; top: 16px;
  color: var(--accent); font-size: 1.1em; font-weight: bold;
  border: 1px solid rgba(255,215,0,0.3); padding: 6px 14px;
  border-radius: 6px; background: rgba(255,215,0,0.08);
}

/* 商店弹窗 */
.shop-overlay { z-index: 300; }
.shop-box {
  background: linear-gradient(135deg, #3d2216, #2c1810);
  border: 3px solid var(--accent); border-radius: 16px;
  padding: 30px 40px; text-align: center; max-width: 620px; width: 90vw;
  max-height: 85vh; overflow-y: auto;
  box-shadow: 0 0 60px rgba(255,215,0,0.3);
  animation: popIn 0.4s ease-out;
}
.shop-box h2 { font-size: 1.6em; margin-bottom: 8px; color: var(--accent); }
.shop-coins { color: #bbb; font-size: 1.1em; margin-bottom: 16px; }
.skin-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 14px; margin: 12px 0;
}
.skin-card {
  border: 2px solid rgba(255,215,0,0.2); border-radius: 12px;
  padding: 12px; text-align: center; transition: all 0.2s;
}
.skin-card.equipped { border-color: var(--accent); background: rgba(255,215,0,0.08); }
.skin-preview {
  width: 100%; aspect-ratio: 1; border-radius: 8px;
  position: relative; overflow: hidden; margin-bottom: 8px;
}
.skin-preview-lines {
  position: absolute; inset: 15%; border: 1px solid;
  opacity: 0.5;
}
.skin-name { font-size: 0.9em; color: var(--text-color); margin-bottom: 6px; }
.skin-badge {
  display: inline-block; background: var(--accent); color: #1a0f0a;
  font-size: 0.8em; padding: 2px 10px; border-radius: 4px; font-weight: bold;
}
.skin-btn { width: 100%; font-size: 0.85em; padding: 5px 8px; }

/* 奖励提示 */
.reward-toast {
  position: fixed; top: 20%; left: 50%; transform: translateX(-50%);
  background: rgba(255,215,0,0.95); color: #1a0f0a;
  padding: 12px 28px; border-radius: 10px; font-size: 1.3em; font-weight: bold;
  z-index: 250; animation: rewardFloat 2s ease-out forwards;
  box-shadow: 0 4px 20px rgba(255,215,0,0.4);
}
@keyframes rewardFloat {
  0%   { opacity: 1; transform: translateX(-50%) translateY(0); }
  70%  { opacity: 1; }
  100% { opacity: 0; transform: translateX(-50%) translateY(-60px); }
}

/* 响应式 */
@media (max-width: 600px) {
  h1 { font-size: 1.1em; margin: 6px 0 2px; letter-spacing: 2px; }
  .btn { padding: 5px 10px; font-size: 0.8em; }
  .btn.large { padding: 10px 24px; font-size: 1em; }
  .status-bar { font-size: 0.85em; margin: 4px 0; min-height: 1.2em; }
  .controls { gap: 6px; margin: 4px 0; padding: 0 6px; }
  .score-board { font-size: 0.85em; gap: 14px; margin-bottom: 2px; }
  .overlay-box { padding: 20px 28px; }
  .overlay-box h2 { font-size: 1.3em; }
  .back-btn { left: 6px; top: 6px; font-size: 0.8em; padding: 3px 8px; }
  .coin-display { right: 6px; top: 6px; font-size: 0.8em; padding: 3px 8px; }
  .shop-box { padding: 16px; }
  .skin-grid { grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)); gap: 8px; }
  #canvas-wrap { margin: 0 auto 8px; }
  canvas { border-radius: 4px; box-shadow: 0 4px 16px rgba(0,0,0,0.5), 0 0 0 2px #8B6914; }
}