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

:root {
  --linen: #f5f0e1;
  --linen-2: #efe7d2;
  --wood: #deb887;
  --wood-deep: #c89b6a;
  --ink: #2b2118;
  --ink-soft: #5a4a38;
  --brown: #8b4513;
  --brown-deep: #6b340e;
  --jade: #3a6b4f;
  --jade-deep: #2c5440;
  --gold: #b8860b;
  --line: rgba(120, 80, 40, .22);
  --line-soft: rgba(120, 80, 40, .14);
  --surface: #fbf7ec;
  --surface-2: #f1e8d4;
  --radius: 14px;
  --radius-lg: 20px;
  --shadow: 0 14px 36px rgba(90, 60, 25, .18);
  --serif: "Kaiti SC", "STKaiti", "楷体", "PingFang SC", "Microsoft YaHei", serif;
}

html, body { height: 100%; overflow: hidden; }

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  font: 16px/1.6 "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  background:
    repeating-linear-gradient(90deg, rgba(255,255,255,.18) 0 2px, transparent 2px 5px),
    repeating-linear-gradient(0deg, rgba(150,110,60,.05) 0 2px, transparent 2px 6px),
    linear-gradient(160deg, #f7f2e6 0%, var(--linen) 50%, #efe6d0 100%);
}

button, select, input { font: inherit; color: inherit; }

a { color: var(--brown); text-decoration: none; }
a:hover { color: var(--gold); }
.foot a { color: inherit; }
.foot a:hover { color: var(--ink); }

.app {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  overflow: hidden;
}

/* ===== 首屏容器（顶栏 + 广告 + 主舞台） ===== */
.game-screen {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* 移动端切换到记录/教程时，game-screen 收缩到自然高度，article 展开 */
.game-screen.stage-collapsed {
  flex: 0 0 auto;
}

/* ===== 顶栏 ===== */
.topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: calc(11px + env(safe-area-inset-top)) 20px 11px;
  background: linear-gradient(120deg, #8b4513, #a35a1f 60%, #7a3a0d);
  color: #fdf6e8;
  border-bottom: 2px solid rgba(60, 30, 8, .35);
  box-shadow: 0 4px 16px rgba(80, 45, 15, .3);
}

.logo { display: flex; flex: 0 0 auto; filter: drop-shadow(0 3px 6px rgba(0, 0, 0, .35)); }
.brand-logo { display: block; border-radius: 9px; }

.topbar__text { flex: 1 1 auto; min-width: 0; }

.topbar__text h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(18px, 2.6vw, 27px);
  letter-spacing: .05em;
  line-height: 1.15;
}

.topbar__text h2 {
  margin: 3px 0 0;
  color: rgba(255, 248, 232, .82);
  font-size: clamp(14px, 1.5vw, 16px);
  font-weight: 500;
}

/* ===== 广告位（纯 CSS 控制显隐） ===== */
.ad-slot { display: none; }
.ad-slot:not(:empty) {
  flex: 0 0 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60px;
  max-height: 60px;
  margin: 10px 16px;
  color: var(--ink-soft);
  font-size: 14px;
  border: 1px dashed var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, .4);
  overflow: hidden;
}

/* ===== 主舞台 ===== */
.stage {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  gap: 18px;
  padding: 14px 20px 16px;
  overflow: hidden;
}

.board {
  flex: 2 1 0;
  min-width: 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

/* ===== 模式切换段控件 ===== */
.mode-switch {
  width: min(100%, 560px);
  display: flex;
  gap: 6px;
  padding: 5px;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--line-soft);
}

.mode-switch__btn {
  flex: 1 1 0;
  min-height: 36px;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--ink-soft);
  font-weight: 500;
  font-size: 15px;
  cursor: pointer;
  transition: background .18s, color .18s;
}

.mode-switch__btn.active {
  background: linear-gradient(135deg, #a35a1f, var(--brown-deep));
  color: #fdf3e3;
  box-shadow: 0 6px 16px rgba(107, 52, 14, .28);
}

/* ===== 信息条 ===== */
.infobar {
  width: min(100%, 560px);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.mode-pill {
  flex: 0 0 auto;
  padding: 5px 12px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--jade), var(--jade-deep));
  color: #f3fbf5;
  font-weight: 400;
  font-size: 13px;
  letter-spacing: .03em;
}

.turn {
  flex: 0 0 auto;
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--ink);
  color: #f7efe0;
  font-weight: 400;
  font-size: 13px;
}

.info-cap, .info-streak {
  flex: 1 1 auto;
  text-align: right;
  color: var(--ink-soft);
  font-size: 14px;
}

.mode-game .info-streak { display: none; }
.mode-puzzle .info-cap { display: none; }

/* ===== 音效图标按钮 ===== */
.btn-sound {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--line-soft);
  border-radius: 50%;
  background: var(--surface);
  color: var(--ink-soft);
  cursor: pointer;
  transition: background .16s, color .16s, border-color .16s, opacity .16s;
}

.btn-sound:hover { background: var(--surface-2); color: var(--ink); border-color: var(--line); }
.btn-sound:active { transform: scale(.94); }

.ico-sound-off { display: none; }
.btn-sound[aria-pressed="false"] { opacity: .5; }
.btn-sound[aria-pressed="false"] .ico-sound-on { display: none; }
.btn-sound[aria-pressed="false"] .ico-sound-off { display: block; }

/* ===== 棋盘 ===== */
.board__frame {
  /* 以高度为基准，宽度由 aspect-ratio 推导，真正 flex 流式 */
  flex: 1 1 auto;
  min-height: 0;
  max-height: min(100%, 650px);
  max-width: min(100%, 650px);
  aspect-ratio: 1 / 1;
  padding: clamp(8px, 1.6vw, 16px);
  border-radius: var(--radius-lg);
  background: linear-gradient(150deg, #e8c79a, var(--wood) 55%, #cfa775);
  box-shadow: var(--shadow), inset 0 0 0 2px rgba(255, 240, 210, .4), inset 0 0 30px rgba(120, 80, 40, .25);
}

#gameCanvas {
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 8px;
  cursor: pointer;
  touch-action: manipulation;
}

.board__status {
  width: min(100%, 560px);
  margin: 0;
  min-height: 20px;
  padding: 0 4px;
  text-align: center;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-soft);
}

/* ===== 选择条 ===== */
.board__bar {
  width: min(100%, 560px);
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  background: var(--surface);
}

.board__bar { display: none; }
.mode-game .bar-game { display: flex; }
.mode-puzzle .bar-puzzle { display: flex; }

.board__bar label {
  flex-shrink: 0;
  color: var(--ink-soft);
  font-size: 14px;
}

.board__bar select {
  flex: 1;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fffdf7;
  font-size: 14px;
  cursor: pointer;
}

/* ===== 按钮区 ===== */
.toolbar {
  width: min(100%, 560px);
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.toolbar { display: none; }
.mode-game .tools-game { display: flex; }
.mode-puzzle .tools-puzzle { display: flex; }

.btn {
  min-height: 38px;
  padding: 7px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 400;
  font-size: 14px;
  cursor: pointer;
  transition: transform .16s ease, background .16s ease, box-shadow .16s ease, border-color .16s ease;
}

.btn:hover { transform: translateY(-1px); background: var(--surface-2); }
.btn:active { transform: translateY(0); }

.btn--primary {
  border-color: transparent;
  background: linear-gradient(135deg, #a35a1f, var(--brown-deep));
  color: #fdf3e3;
  box-shadow: 0 8px 20px rgba(107, 52, 14, .3);
}
.btn--primary:hover { background: linear-gradient(135deg, #b3661f, #7a3a0d); }

.btn--toggle[aria-pressed="false"] { color: var(--ink-soft); background: var(--surface-2); opacity: .8; }
.btn--lg { min-height: 44px; padding: 10px 26px; font-size: 15px; }

/* ===== 侧面板 ===== */
.panel {
  flex: 1 1 320px;
  max-width: 400px;
  min-width: 290px;
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
  padding-right: 4px;
  padding-bottom: 14px;
  scrollbar-width: thin;
  scrollbar-color: rgba(139, 69, 19, .3) transparent;
}

.panel::-webkit-scrollbar { width: 5px; }
.panel::-webkit-scrollbar-thumb { background: rgba(139, 69, 19, .25); border-radius: 99px; }
.panel::-webkit-scrollbar-thumb:hover { background: rgba(139, 69, 19, .45); }

.mode-game .card-puzzle { display: none; }
.mode-puzzle .card-game { display: none; }

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  padding: 15px;
}

.card h3 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: 17px;
  letter-spacing: .03em;
  color: var(--brown-deep);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

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

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 9px 10px;
  border-radius: 11px;
  background: var(--surface-2);
  border: 1px solid var(--line-soft);
}

.stat-item span { color: var(--ink-soft); font-size: 13px; }
.stat-item strong { font-size: 18px; color: var(--ink); }

.tip-note {
  margin: 12px 0 0;
  padding: 10px 12px;
  border-radius: 11px;
  background: rgba(184, 134, 11, .1);
  border: 1px solid rgba(184, 134, 11, .25);
  color: var(--ink-soft);
  font-size: 14px;
}

.puzzle-desc {
  margin: 0 0 12px;
  padding: 10px 12px;
  border-radius: 11px;
  background: rgba(58, 107, 79, .1);
  border: 1px solid rgba(58, 107, 79, .25);
  color: var(--jade-deep);
  font-size: 14px;
  font-weight: 600;
}

.card-history { flex: 1 1 auto; min-height: 100px; display: flex; flex-direction: column; overflow: hidden; }

.move-list {
  flex: 1 1 auto;
  min-height: 0;
  margin: 0;
  padding: 0 2px 8px 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  grid-auto-rows: min-content;
  gap: 6px;
  list-style: none;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(139, 69, 19, .25) transparent;
}

.move-list::-webkit-scrollbar { width: 4px; }
.move-list::-webkit-scrollbar-thumb { background: rgba(139, 69, 19, .25); border-radius: 99px; }

.move-list button {
  width: 100%;
  min-height: 32px;
  padding: 5px 9px;
  border: 1px solid var(--line-soft);
  border-radius: 9px;
  background: var(--surface-2);
  color: var(--ink-soft);
  text-align: left;
  font-size: 14px;
  cursor: pointer;
  transition: background .15s ease, color .15s ease;
}

.move-list button:hover { background: #e9ddc2; color: var(--ink); }
.move-list button:disabled { opacity: .5; cursor: default; }
.move-list .active button { background: var(--brown); color: #fff5e6; border-color: var(--brown); font-weight: 700; }

/* ===== 文章 / 教学内容 ===== */
.article {
  flex: 0 0 0;
  min-height: 0;
  overflow: hidden;
  margin: 0 20px;
  border-radius: var(--radius);
}

.article.visible {
  flex: 1 1 auto;
  overflow-y: auto;
  padding: 18px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.article__panel { display: none; max-width: 940px; margin: 0 auto; }
.article__panel.active { display: block; }

.article__panel h2 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: clamp(19px, 3vw, 26px);
  color: var(--brown-deep);
}

.article__panel h3 { color: var(--brown-deep); }
.article__panel p { color: var(--ink-soft); }
.article__panel section + section { margin-top: 26px; }

.record-summary {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 16px;
}

.record-summary span {
  padding: 12px;
  border-radius: 12px;
  background: var(--surface-2);
  border: 1px solid var(--line-soft);
  text-align: center;
  font-size: 14px;
  color: var(--ink-soft);
}

.record-summary strong { display: block; margin-top: 4px; font-size: 22px; color: var(--jade-deep); }

.rec-subtitle { margin: 6px 0 10px; font-size: 16px; }
.recent-list { margin: 0 0 12px; padding-left: 20px; display: grid; gap: 8px; }
.recent-list li { color: var(--ink-soft); font-size: 14px; }
.recent-list .recent-hide { display: none; }
.recent-list .recent-empty { list-style: none; margin-left: -20px; color: #998; }
.rec-note { font-size: 14px; }

.guide-list { padding-left: 22px; color: var(--ink-soft); }
.guide-list li { margin: 8px 0; }
.guide-list strong { color: var(--brown-deep); }

details {
  margin-top: 10px;
  padding: 11px 13px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface-2);
}

summary { cursor: pointer; color: var(--brown-deep); font-weight: 700; }
details p { margin: 8px 0 0; }

/* ===== 底部 TabBar（移动端） ===== */
.tabbar {
  flex-shrink: 0;
  order: 999;
  display: flex;
  gap: 2px;
  padding: 5px 8px calc(6px + env(safe-area-inset-bottom));
  background: linear-gradient(180deg, #7a3a0d, #5d2c08);
  border-top: 1px solid rgba(40, 18, 4, .5);
}

.tab {
  flex: 1 1 0;
  min-width: 0;
  min-height: 42px;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  border: none;
  border-radius: 10px;
  background: transparent;
  color: rgba(255, 240, 220, .5);
  font-weight: 400;
  font-size: 11px;
  letter-spacing: .02em;
  cursor: pointer;
  transition: color .18s;
}

.tab__ico { display: block; width: 20px; height: 20px; transition: transform .18s, opacity .18s; }

.tab.active {
  color: #fff3e0;
}

.tab.active .tab__ico { transform: scale(1.1); }


/* ===== 页脚（PC） ===== */
.foot {
  display: none;
  flex: 0 0 auto;
  gap: 14px;
  justify-content: center;
  align-items: center;
  padding: 9px 16px;
  color: var(--ink-soft);
  font-size: 14px;
  background: rgba(222, 184, 135, .25);
  border-top: 1px solid var(--line-soft);
}

/* ===== 结果弹窗 ===== */
.overlay {
  position: fixed;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(50, 32, 12, .55);
  backdrop-filter: blur(5px);
  z-index: 50;
}

.overlay.show { display: flex; }

.overlay__card {
  width: min(100%, 360px);
  padding: 28px 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(160deg, #fdf8ec, #f1e6cf);
  box-shadow: var(--shadow);
  text-align: center;
}

.overlay__icon { margin: 0; font-size: 48px; }
.overlay__title { margin: 8px 0 4px; font-family: var(--serif); font-size: 24px; font-weight: 800; color: var(--brown-deep); }
.overlay__detail { margin: 0 0 18px; color: var(--ink-soft); }

/* ===== PC ===== */
@media (min-width: 900px) {
  /*
   * PC 端：body 正常滚动，game-screen 精确锁定 100dvh，
   * 不依赖任何 calc 减法，彻底规避多浏览器高度计算差异。
   * article / footer 在 game-screen 之后，随页面自然滚动。
   */
  html, body { height: auto; min-height: 100dvh; overflow: visible; }

  .app {
    height: auto;
    min-height: 100dvh;
    overflow: visible;
  }

  /* game-screen = 完整视口高度，内部 flex 分配：顶栏 + 广告 + 舞台 */
  .game-screen {
    height: 100dvh;
    flex: none;
    overflow: hidden;
  }

  /* PC 无标签切换，stage-collapsed 不生效，但保留防御性重置 */
  .game-screen.stage-collapsed {
    height: 100dvh;
    flex: none;
  }

  /* stage 在 game-screen 内自然填满剩余高度，无需 max-height calc */
  .stage {
    flex: 1 1 auto;
    min-height: 0;
    overflow: hidden;
    justify-content: center;
  }

  /* board 列宽受限，高度由 stage flex 分配，PC 端加大到 650px */
  .board {
    flex: 0 1 650px;
    overflow: hidden;
  }

  /* PC 端 board 内元素宽度跟随棋盘，不限死 560px */
  .mode-switch,
  .infobar,
  .board__status {
    width: 100%;
    max-width: 100%;
  }

  /* panel 内的下拉条和按钮区宽度充满，样式调整 */
  .panel .board__bar {
    width: 100%;
    max-width: 100%;
  }

  .panel .toolbar {
    width: 100%;
    max-width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
    padding: 4px 0 2px;
    background: none;
    border: none;
  }

  .tabbar { display: none; }

  .article {
    display: block;
    flex: 0 0 auto;
    overflow: visible;
    padding: 24px;
    margin: 0 auto 20px;
    max-width: 1060px;
    width: calc(100% - 40px);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface);
  }
  .article__panel { display: block; }
  .article__panel + .article__panel {
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--line-soft);
  }
  .foot { display: flex; }
}

/* ===== 移动端 ===== */
@media (max-width: 899px) {
  .topbar { padding-left: 14px; padding-right: 14px; gap: 10px; }
  .ad-slot:not(:empty) { margin: 8px 14px; }

  /* 移动端隐藏模式切换按钮，底部导航已覆盖该功能 */
  .mode-switch { display: none; }

  /* 减小间距，并把棋盘+控件整体垂直居中，避免顶部堆叠、底部留大片空白 */
  .stage { flex-direction: column; justify-content: center; gap: 6px; padding: 8px 14px 10px; }
  .stage.collapsed { flex: 0 0 0; padding-top: 0; padding-bottom: 0; gap: 0; overflow: hidden; }

  /* 对弈/死活题 tab 时只隐藏 panel 里的卡片，bar 和 toolbar 保留在棋盘下方 */
  .stage:not(.collapsed) .panel .card { display: none; }
  .stage:not(.collapsed) .panel {
    gap: 6px;
  }

  /* board 不再撑满高度（改由 stage 居中分配），内容溢出时仍可纵向滚动 */
  .board { flex: 0 1 auto; min-height: 0; overflow-y: auto; overflow-x: hidden; gap: 6px; }

  /*
   * 棋盘框：移动端不再用 flex 撑满高度（会把正方形拉成竖向矩形）。
   * 改为以宽度为基准、aspect-ratio 推导高度，保持正方形；
   * 宽度同时受可视高度约束，确保正方形整体能放下、且不被竖向拉伸。
   */
  .board__frame {
    flex: 0 0 auto;
    width: min(100%, 560px, calc(100dvh - 300px));
    height: auto;
    max-width: 560px;
    max-height: none;
  }

  /* 工具栏改为单行横向滚动，节省纵向高度 */
  .toolbar {
    flex-wrap: nowrap;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    justify-content: flex-start;
    scrollbar-width: none;
    padding-bottom: 4px;
  }
  .toolbar::-webkit-scrollbar { display: none; }
  .toolbar .btn { flex: 0 0 auto; white-space: nowrap; }

  .panel {
    max-width: none;
    min-width: 0;
    width: 100%;
    flex: 0 0 auto;
    overflow: visible;
  }

  /* 移动端 panel 内的 bar/toolbar 紧凑化，减少占用棋盘高度 */
  .stage:not(.collapsed) .panel .board__bar {
    padding: 5px 10px;
  }
  .stage:not(.collapsed) .panel .toolbar {
    padding-bottom: 2px;
  }
  .stage:not(.collapsed) .panel .btn {
    min-height: 34px;
    padding: 5px 13px;
    font-size: 14px;
  }

  .article { margin: 0 14px; }
  .article.visible { margin: 10px 14px 14px; }
}

@media (max-width: 560px) {
  body { font-size: 15px; }
  .topbar__text h1 { font-size: 18px; }
  /* 小屏适配：棋盘框继续以宽度为基准保持正方形，宽度受可视高度约束 */
  .board__frame {
    width: min(100%, calc(100dvh - 285px));
    max-width: 100%;
  }
  /* 工具栏按钮保持 flex: 0 0 auto，不被 wrap 分列 */
  .toolbar .btn { flex: 0 0 auto; font-size: 14px; }
  .infobar { gap: 4px; flex-wrap: nowrap; }
  /* infobar 不换行，改为缩小字号而非独占一行 */
  .mode-pill, .turn { padding: 5px 10px; font-size: 13px; }
  .info-cap, .info-streak { font-size: 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
}