/* ============================================================
  * 打字测试 · 文房风深色主题
   配色：墨黑底 #0a0907 / 暖白字 #f5efe0 / 朱砂红 #c8453a / 暖灰 #8a8378
   字体：Noto Sans SC（正文）/ Noto Serif SC（标题/字帖感）
   ============================================================ */

/* ---------- 1. 设计令牌 ---------- */
:root {
  /* 颜色 */
  --bg: #0a0907;              /* 墨黑底，略带暖 */
  --bg-soft: #141210;          /* 卡片底 */
  --bg-elev: #1c1916;          /* 浮层底 */
  --fg: #f5efe0;               /* 暖白主文字 */
  --fg-mute: #8a8378;          /* 暖灰次要文字 */
  --fg-dim: #5a5550;           /* 更暗的灰 */
  --ruby: #9a9388;             /* 五笔编码标注小字 */
  --accent: #c8453a;           /* 朱砂红（当前字、选中态） */
  --accent-soft: rgba(200, 69, 58, 0.12);
  --accent-line: rgba(200, 69, 58, 0.4);
  --border: rgba(245, 239, 224, 0.08);
  --border-strong: rgba(245, 239, 224, 0.16);
  --ok: #6a8a5a;               /* 正确字绿 */
  --err: #c8453a;              /* 错字红 */
  --gold: #d4af37;             /* 段位章金 */

  /* 字体 */
  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", ui-sans-serif, system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Consolas", monospace;

  /* 尺寸 */
  --max-w: 880px;              /* 主内容最大宽度 */
  --pad-w: 820px;              /* 字帖区宽度 */
  --radius: 8px;
  --radius-lg: 14px;
  --shadow: 0 1px 0 rgba(0,0,0,0.4), 0 8px 24px rgba(0,0,0,0.3);
}

/* 亮色主题（宣纸风） */
body.light {
  --bg: #faf6ee;               /* 宣纸米白底 */
  --bg-soft: #f2ece0;          /* 卡片底 */
  --bg-elev: #ffffff;          /* 浮层底 */
  --fg: #2a2620;               /* 墨黑主文字 */
  --fg-mute: #6a6358;          /* 暖灰次要文字 */
  --fg-dim: #9a9388;           /* 更暗的灰 */
  --ruby: #6f6a60;             /* 五笔编码标注小字（宣纸底需更深） */
  --accent: #b8392e;           /* 朱砂红 */
  --accent-soft: rgba(184, 57, 46, 0.10);
  --accent-line: rgba(184, 57, 46, 0.35);
  --border: rgba(42, 38, 32, 0.08);
  --border-strong: rgba(42, 38, 32, 0.16);
  --ok: #4a7a3a;
  --err: #b8392e;
  --gold: #b8941f;
  --shadow: 0 1px 0 rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.08);
}
body.light.grain { background-image: none; }

/* 亮色主题：顶栏与字帖引导遮罩改宣纸底（弹窗遮罩保持深色以聚焦内容） */
body.light .site-header {
  background: rgba(250, 246, 238, 0.85);
}
body.light .pad-guide {
  background: rgba(250, 246, 238, 0.66);
}

/* ---------- 2. 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
/* grain 噪点纹理（极淡） */
body.grain::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

a { color: var(--fg); text-decoration: none; transition: color .15s; }
a:hover { color: var(--accent); }
button { font-family: inherit; cursor: pointer; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--accent); color: #fff; padding: 8px 14px; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

h1, h2, h3 { font-family: var(--font-serif); font-weight: 600; line-height: 1.3; margin: 0 0 0.6em; }
h1 { font-size: 2.25rem; }
h2 { font-size: 1.5rem; margin-top: 2.4em; }
h3 { font-size: 1.15rem; margin-top: 1.2em; }
p { margin: 0 0 1em; }
strong { color: var(--fg); font-weight: 600; }

/* ---------- 3. 顶部导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 9, 7, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: 1080px; margin: 0 auto;
  display: flex; align-items: center; gap: 24px;
  padding: 12px 24px;
}
.logo {
  display: inline-flex; align-items: center; gap: 10px;
  flex-shrink: 0;
}
.logo-seal {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  background: var(--accent); color: #fff;
  font-family: var(--font-serif); font-size: 16px; font-weight: 600;
  border-radius: 6px;
  transition: transform .3s;
}
.logo:hover .logo-seal { transform: rotate(-6deg); }
.logo-text { font-family: var(--font-serif); font-size: 16px; font-weight: 600; line-height: 1.1; }
.logo-text small { display: block; font-family: var(--font-sans); font-size: 11px; font-weight: 400; color: var(--fg-mute); margin-top: 1px; }

.site-nav {
  display: flex; flex-wrap: wrap; gap: 4px;
  flex: 1; min-width: 0;
}
.site-nav a {
  padding: 6px 12px; border-radius: 6px;
  font-size: 14px; color: var(--fg-mute);
}
.site-nav a:hover, .site-nav a[aria-current="page"] {
  color: var(--fg); background: var(--bg-soft);
}
.header-actions { display: flex; gap: 6px; flex-shrink: 0; }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 6px;
  background: transparent; border: 1px solid transparent;
  color: var(--fg-mute);
}
.icon-btn:hover { color: var(--fg); background: var(--bg-soft); }

/* ---------- 4. 主区域 ---------- */
.site-main {
  flex: 1; width: 100%;
  position: relative; z-index: 1;
}

/* ---------- 5. 测速区 ---------- */
.typing-area {
  max-width: var(--pad-w);
  margin: 32px auto 0;
  padding: 0 24px;
}

/* 设置栏 */
.settings-bar {
  display: flex; flex-direction: column; gap: 8px;
  margin-bottom: 16px;
}
.settings-group {
  display: flex; flex-wrap: wrap; gap: 4px;
  align-items: center;
}
.settings-group.opts { justify-content: flex-end; }
.settings-group .sep {
  display: inline-block; width: 1px; height: 18px;
  background: var(--border-strong); margin: 0 6px;
}
.mode-btn, .toggle-btn {
  padding: 5px 12px; border-radius: 6px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--fg-mute);
  font-size: 14px;
  transition: all .15s;
}
.mode-btn:hover, .toggle-btn:hover { color: var(--fg); background: var(--bg-soft); }
.mode-btn.active {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent-line);
}
.toggle-btn.on {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent-line);
}

/* 实时统计条 */
.stats-bar {
  display: flex; align-items: baseline; justify-content: space-between;
  padding: 4px 2px 8px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
  font-variant-numeric: tabular-nums;
}
.stat { display: flex; flex-direction: column; gap: 2px; }
.stat.best { text-align: left; }
.stat.current { text-align: center; }
.stat.acc { text-align: right; }
.stat-label { font-size: 12px; color: var(--fg-dim); }
.stat-value { font-size: 18px; color: var(--fg); font-weight: 500; }
.stat.current .stat-value { color: var(--accent); font-size: 22px; }

/* 字帖区 */
.pad {
  position: relative;
  min-height: 220px;
  padding: 24px 8px;
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
  border: 1px solid var(--border);
  cursor: text;
  outline: none;
  overflow: hidden;
}
.pad:focus { border-color: var(--accent-line); box-shadow: 0 0 0 3px var(--accent-soft); }
.pad-source {
  font-family: var(--font-serif);
  font-size: 22px;
  line-height: 2.1;
  letter-spacing: 0.04em;
  color: var(--fg-dim);
  word-break: break-all;
  user-select: none;
}
.pad-source .char { display: inline; transition: color .08s; }
.pad-source .char.done { color: var(--fg); opacity: 0.7; }
.pad-source .char.ok { color: var(--ok); opacity: 1; }
.pad-source .char.err { color: var(--err); border-bottom: 1.5px solid var(--err); }
.pad-source .char.cur {
  color: var(--accent);
  background: var(--accent-soft);
  border-bottom: 2px solid var(--accent);
  border-radius: 2px;
}
.pad-source .char.cur.blind { color: transparent; background: var(--accent-soft); border-bottom-color: var(--accent); }

/* 五笔编码标注：汉字上方小字显示全码 */
.pad-source.ruby-on { line-height: 2.55; }
.pad-source .char.ruby {
  display: inline-block;
  text-align: center;
  line-height: 1;
}
.pad-source .char-code {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.3;
  letter-spacing: .5px;
  height: 14px;
  color: var(--ruby);
  opacity: .85;
  white-space: nowrap;
}
.pad-source .char-glyph { display: block; line-height: 1.55; }
.pad-source .char.ruby.done .char-code { opacity: .35; }
.pad-source .char.ruby.cur .char-code { color: var(--accent); opacity: 1; font-weight: 700; }
.pad-source .char.ruby.err .char-code { color: var(--err); opacity: .9; }
/* 当前/错误高亮只落在字形上，不罩住编码 */
.pad-source .char.ruby.cur,
.pad-source .char.ruby.err { background: transparent; border-bottom: none; }
.pad-source .char.ruby.cur .char-glyph {
  color: var(--accent);
  background: var(--accent-soft);
  border-bottom: 2px solid var(--accent);
  border-radius: 2px;
}
.pad-source .char.ruby.err .char-glyph { color: var(--err); border-bottom: 1.5px solid var(--err); }
.pad-source .char.ruby.cur.blind .char-glyph { color: transparent; }
@media (max-width: 640px) {
  .pad-source .char-code { font-size: 9px; letter-spacing: .3px; }
}

/* 引导覆盖层：初始覆盖整个字帖，点击或首字落笔后隐藏 */
.pad-guide {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(10, 9, 7, 0.65);
  backdrop-filter: blur(2px);
  cursor: pointer;
  transition: opacity .25s, visibility .25s;
  z-index: 5;
}
.pad-guide.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}
.guide-text {
  padding: 10px 24px;
  font-size: 15px;
  color: var(--fg-mute);
  border: 1px solid var(--border-strong);
  border-radius: 24px;
  background: var(--bg-soft);
  transition: color .15s, border-color .15s;
}
.pad-guide:hover .guide-text {
  color: var(--accent);
  border-color: var(--accent-line);
}

/* 打字区底部 */
.pad-footer {
  display: flex; align-items: center; gap: 16px;
  margin-top: 12px;
  font-size: 13px; color: var(--fg-dim);
}
.pad-footer .pad-spacer { flex: 1; }
.pad-note {
  font-family: var(--font-serif);
  font-size: 13px;
  color: var(--fg-mute);
  flex-shrink: 0;
}
.ghost-btn, .primary-btn {
  padding: 6px 14px; border-radius: 6px;
  font-size: 13px;
  transition: all .15s;
}
.ghost-btn {
  background: transparent;
  border: 1px solid var(--border-strong);
  color: var(--fg-mute);
}
.ghost-btn:hover { color: var(--fg); border-color: var(--fg-mute); }
.primary-btn {
  background: var(--accent); border: 1px solid var(--accent);
  color: #fff; font-weight: 500;
}
.primary-btn:hover { background: #b03a30; }

/* 命令面板 */
.command-palette {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(10, 9, 7, 0.6);
  backdrop-filter: blur(4px);
  display: flex; align-items: flex-start; justify-content: center;
  padding-top: 12vh;
}
.command-palette[hidden] { display: none; }
.cmd-box {
  width: min(560px, 92vw);
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
#cmd-input {
  width: 100%; padding: 14px 18px;
  background: transparent; border: 0; outline: none;
  color: var(--fg); font-size: 15px; font-family: inherit;
  border-bottom: 1px solid var(--border);
}
#cmd-input::placeholder { color: var(--fg-dim); }
.cmd-list { list-style: none; margin: 0; padding: 6px; max-height: 320px; overflow-y: auto; }
.cmd-list li {
  padding: 8px 12px; border-radius: 6px;
  font-size: 14px; color: var(--fg-mute);
  cursor: pointer;
}
.cmd-list li.active, .cmd-list li:hover { background: var(--bg-soft); color: var(--fg); }

/* 结算面板 */
.result-panel {
  position: fixed; inset: 0; z-index: 90;
  background: rgba(10, 9, 7, 0.78);
  backdrop-filter: blur(8px);
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
}
.result-panel[hidden] { display: none; }
.result-inner {
  width: min(680px, 94vw);
  max-height: 92vh; overflow-y: auto;
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 40px rgba(0,0,0,0.5);
  padding: 32px 36px;
  display: flex; flex-direction: column; gap: 28px;
}

/* --- 第 1 层：WPM + 段位印章 --- */
.result-head {
  display: flex; align-items: flex-start; gap: 28px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}
.result-seal {
  display: inline-flex; align-items: center; justify-content: center;
  width: 80px; height: 80px;
  background: var(--accent); color: #fff;
  font-family: var(--font-serif); font-size: 22px; font-weight: 600;
  border-radius: 12px;
  flex-shrink: 0;
  box-shadow: inset 0 0 0 3px rgba(255,255,255,0.12);
  letter-spacing: 0.05em;
}
.result-main { flex: 1; min-width: 0; }
.result-wpm {
  font-size: 56px; font-weight: 600; color: var(--fg);
  font-variant-numeric: tabular-nums; line-height: 1;
  letter-spacing: -0.02em;
}
.result-wpm small { font-size: 15px; color: var(--fg-mute); margin-left: 10px; font-weight: 400; }
.result-meta { font-size: 13px; color: var(--fg-mute); margin-top: 8px; display: flex; gap: 16px; flex-wrap: wrap; }
.result-meta span { display: inline-flex; align-items: center; gap: 4px; }
.result-meta b { color: var(--fg); font-weight: 500; }

/* --- 第 2 层：统计数字（2×2 网格，竖排不挤） --- */
.result-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px 24px;
}
.result-grid > div {
  display: flex; align-items: baseline; gap: 10px;
  padding: 10px 14px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: 8px;
}
.r-label { font-size: 12px; color: var(--fg-dim); flex-shrink: 0; }
.r-value { font-size: 18px; color: var(--fg); font-variant-numeric: tabular-nums; font-weight: 500; }

/* --- 第 3 层：逐秒速度曲线 --- */
.result-chart {
  height: 60px;
  display: flex; align-items: flex-end; gap: 3px;
  padding: 8px 0;
}
.result-chart .bar {
  flex: 1; background: rgba(200, 69, 58, 0.25); border-top: 2px solid var(--accent);
  min-height: 2px; border-radius: 2px 2px 0 0;
  transition: height .3s;
}

/* --- 第 4 层：易错字 + 犹豫字 TOP5 --- */
.result-errors {
  display: grid; grid-template-columns: 1fr 1fr; gap: 24px;
}
.err-block h4 {
  font-family: var(--font-sans); font-size: 12px; color: var(--fg-dim);
  margin: 0 0 10px; font-weight: 400; letter-spacing: 0.12em;
  text-transform: uppercase;
}
.err-list { margin: 0; padding: 0; list-style: none; }
.err-list li {
  display: flex; align-items: center; gap: 8px;
  padding: 4px 0;
  font-size: 14px; color: var(--fg-mute);
  border-bottom: 1px dashed var(--border);
}
.err-list li:last-child { border-bottom: none; }
.err-list .rank {
  display: inline-flex; align-items: center; justify-content: center;
  width: 18px; height: 18px;
  font-size: 11px; color: var(--fg-dim);
  border-radius: 4px; background: rgba(255,255,255,0.04);
  flex-shrink: 0;
}
.err-list .char-text { color: var(--fg); font-family: var(--font-serif); font-size: 16px; }
.err-list .char-count { margin-left: auto; font-size: 12px; color: var(--fg-dim); }

/* --- 第 5 层：底部按钮 --- */
.result-actions {
  display: flex; gap: 10px; flex-wrap: wrap;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}
.result-actions .primary-btn { flex: 1; min-width: 180px; padding: 10px 20px; font-size: 15px; }
.result-actions .ghost-btn { flex: 0 0 auto; padding: 10px 18px; }

/* ---------- 工具按钮组（音效/键位图/换一段/命令） ---------- */
.settings-group.tools {
  justify-content: flex-end;
  gap: 2px;
}
.icon-btn, .icon-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  border-radius: 6px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--fg-mute);
  transition: all .15s;
  cursor: pointer;
}
.icon-btn:hover, .icon-toggle:hover {
  color: var(--fg);
  background: var(--bg-soft);
}
.icon-toggle.on {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: var(--accent-line);
}
.icon-toggle.on svg { stroke: var(--accent); }

/* ---------- 实时键位图 ---------- */
.keyboard-map {
  display: flex; flex-direction: column; gap: 6px;
  padding: 16px;
  margin-bottom: 16px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.keyboard-map[hidden] { display: none; }
.kb-row { display: flex; gap: 5px; justify-content: center; }
.kb-row kbd {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 30px; height: 38px;
  padding: 0 8px;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--fg-mute);
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  box-shadow: 0 2px 0 var(--border-strong);
  transition: all .05s;
}
.kb-row kbd.wide { min-width: 60px; }
.kb-row kbd.space { flex: 1; max-width: 240px; }
.kb-row kbd.active {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent-line);
  box-shadow: 0 0 0 2px var(--accent-soft);
  transform: translateY(1px);
}

/* ---------- 自定义文本弹窗 ---------- */
.custom-modal {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(10, 9, 7, 0.6);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
}
.custom-modal[hidden] { display: none; }
.modal-box {
  width: min(560px, 92vw);
  background: var(--bg-elev);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 24px;
}
.modal-box h3 {
  font-size: 18px; margin: 0 0 8px; color: var(--fg);
}
.modal-hint {
  font-size: 13px; color: var(--fg-dim); margin: 0 0 16px;
}
#custom-text {
  width: 100%;
  padding: 12px 14px;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  color: var(--fg);
  font-size: 15px;
  line-height: 1.7;
  resize: vertical;
  font-family: var(--font-sans);
  box-sizing: border-box;
}
#custom-text:focus { outline: none; border-color: var(--accent-line); }
.modal-actions {
  display: flex; justify-content: flex-end; gap: 10px;
  margin-top: 16px;
}

/* ---------- 6. SEO 长文区 ---------- */
.seo-content {
  max-width: var(--max-w);
  margin: 80px auto 0;
  padding: 0 24px;
  font-size: 15px;
  color: var(--fg);
}
.seo-content .lead {
  font-size: 17px; color: var(--fg-mute);
  margin-top: 8px;
}
.four-ways {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
  margin: 16px 0 24px;
}
.way-card {
  padding: 18px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.way-card h3 { margin-top: 0; color: var(--accent); }

.table-wrap { overflow-x: auto; margin: 16px 0; }
table.speed-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.speed-table th, .speed-table td {
  padding: 10px 14px; text-align: left;
  border-bottom: 1px solid var(--border);
}
.speed-table th { color: var(--fg-dim); font-weight: 400; font-size: 13px; }
.speed-table td:first-child { color: var(--accent); font-family: var(--font-serif); }

.tips-list { list-style: none; counter-reset: tip; padding: 0; margin: 16px 0 24px; }
.tips-list li {
  counter-increment: tip;
  position: relative;
  padding-left: 44px;
  margin-bottom: 18px;
}
.tips-list li::before {
  content: counter(tip);
  position: absolute; left: 0; top: 0;
  width: 30px; height: 30px;
  display: flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--accent);
  border-radius: 50%;
  font-family: var(--font-serif); font-size: 14px; font-weight: 600;
}
.tips-list h3 { margin: 0 0 4px; color: var(--fg); }

.entry-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px;
  margin: 16px 0 24px;
}
.entry-grid a {
  display: block; padding: 16px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all .15s;
}
.entry-grid a:hover {
  border-color: var(--accent-line);
  transform: translateY(-1px);
}
.entry-grid a h3 { margin: 0 0 4px; color: var(--fg); font-size: 15px; }
.entry-grid a p { margin: 0; color: var(--fg-mute); font-size: 13px; }

/* ---------- 7. 用户证言 ---------- */
.testimonials {
  max-width: var(--max-w);
  margin: 64px auto 0;
  padding: 0 24px;
}
.testimonial-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
  margin-top: 16px;
}
.testimonial-grid blockquote {
  margin: 0; padding: 20px;
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  font-size: 14px; color: var(--fg);
}
.testimonial-grid cite { display: block; margin-top: 10px; color: var(--fg-mute); font-size: 13px; font-style: normal; }

/* ---------- 8. FAQ ---------- */
.faq {
  max-width: var(--max-w);
  margin: 64px auto 0;
  padding: 0 24px;
}
.faq details {
  border-bottom: 1px solid var(--border);
  padding: 4px 0;
}
.faq summary {
  padding: 14px 0; cursor: pointer;
  font-size: 15px; color: var(--fg);
  list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; color: var(--fg-dim); font-size: 18px;
  transition: transform .2s;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq summary:hover { color: var(--accent); }
.faq .faq-a {
  padding: 0 0 14px;
  color: var(--fg-mute); font-size: 14px; line-height: 1.7;
}

/* ---------- 9. 侧边导航 ---------- */
.side-nav { display: none; } /* 小屏默认隐藏 */

/* ---------- 9a. 页脚 ---------- */
.site-footer {
  margin-top: 80px;
  padding: 24px;
  text-align: center;
  border-top: 1px solid var(--border);
  color: var(--fg-dim);
  font-size: 13px;
}
.site-footer .copyright { margin: 4px 0 0; }

/* ---------- 9b. 大屏侧边栏（>= 1100px） ---------- */
@media (min-width: 1100px) {
  /* 整体用 grid：header/footer 跨两列，aside + main 同一行 */
  body {
    display: grid;
    grid-template-columns: 160px 1fr;
    grid-template-areas:
      "header header"
      "side   main"
      "footer footer";
    gap: 0 24px;
    align-items: start;
    max-width: calc(50% + 624px);
    margin: 0 auto;
  }
  .site-header { grid-area: header; }
  .site-footer { grid-area: footer; }
  .side-nav {
    grid-area: side;
    display: block;
    position: sticky;
    top: 76px;
    margin-top: 64px;
    width: 160px;
    max-height: calc(100vh - 10rem);
    overflow-y: auto;
    padding: 12px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--bg-soft);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    scrollbar-width: none;
  }
  .side-nav::-webkit-scrollbar { display: none; }
  .side-nav nav { display: flex; flex-direction: column; gap: 14px; }

  /* main 占满右列，内部再居中内容 */
  .site-main {
    grid-area: main;
    max-width: 880px;
    margin: 0 auto;
    width: 100%;
  }

  /* 分组 */
  .side-group { display: flex; flex-direction: column; gap: 2px; }
  .side-group-title {
    display: flex; align-items: center; gap: 6px;
    font-size: 11px; font-weight: 500;
    letter-spacing: 0.12em;
    color: var(--fg-dim);
    padding: 4px 8px 6px;
    margin: 0;
    border-bottom: 1px solid var(--border);
  }
  .side-group-title svg { color: var(--accent); flex-shrink: 0; }

  /* 导航项 */
  .side-group a {
    display: flex; align-items: center; gap: 8px;
    padding: 4px 8px;
    font-size: 13px; line-height: 1.6;
    color: var(--fg-mute);
    border-radius: 6px;
    transition: background .12s, color .12s;
  }
  .side-group a:hover {
    background: rgba(245, 239, 224, 0.05);
    color: var(--fg);
  }
  .side-group a.active {
    color: var(--accent);
    font-weight: 500;
  }
  .side-group a.active .dot { background: var(--accent); }
  .side-group a .dot {
    display: inline-block;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: transparent;
    flex-shrink: 0;
  }
}

/* ---------- 10. 响应式 ---------- */
/* 中屏 (721~1099px)：恢复 body flex column，隐藏侧栏 */
@media (max-width: 1099px) {
  body { display: flex !important; flex-direction: column !important; }
  .side-nav { display: none !important; }
  .site-main { max-width: none; margin: 0; width: 100%; }
}
/* 小屏 */
@media (max-width: 720px) {
  .header-inner { gap: 12px; padding: 10px 16px; flex-wrap: wrap; }
  .site-nav { order: 3; width: 100%; overflow-x: auto; flex-wrap: nowrap; padding-bottom: 4px; }
  .site-nav a { white-space: nowrap; }
  .logo-text small { display: none; }
  .typing-area { padding: 0 16px; margin-top: 20px; }
  .pad-source { font-size: 19px; line-height: 2; }
  .seo-content, .testimonials, .faq { padding: 0 16px; }
  .four-ways, .entry-grid, .testimonial-grid, .result-errors { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: repeat(2, 1fr); }
  h1 { font-size: 1.85rem; }
  h2 { font-size: 1.3rem; }
}

/* ---------- 11. 工具类 ---------- */
[hidden] { display: none !important; }