/* ==========================================================================
   外贸英语 · 邮件英语学习站 —— 本站正文样式
   --------------------------------------------------------------------------
   只依赖 web-common-style 的 8 套主题变量（--color-*）。
   ⚠️ 任何颜色都必须走变量，禁止硬编码色值 —— 否则 5 套浅色主题下会漏深色。
   页眉 / 页脚样式在 header.css / footer.css，本文件不重复定义。
   ========================================================================== */

/* ---------- 主题不变的语义色（与站群约定一致：accent 不随主题变） ---------- */
:root {
  --color-accent: #f59e0b;
  --color-accent-light: #fbbf24;
  --color-success: #22c55e;
  --color-danger: #ef4444;

  --maxw: 1280px;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 18px;
  --sh-1: 0 1px 2px rgba(0, 0, 0, .04), 0 8px 24px -12px rgba(0, 0, 0, .18);
  --sh-2: 0 18px 48px -24px rgba(0, 0, 0, .35);
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-sans, 'Inter', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--color-brand-light); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }

img { max-width: 100%; }

h1, h2, h3, h4 { line-height: 1.25; margin: 0; font-weight: 800; letter-spacing: -.01em; }

code, kbd, .mono { font-family: var(--font-mono, ui-monospace, Consolas, monospace); }

::selection { background: color-mix(in srgb, var(--color-brand-light) 32%, transparent); }

/* 焦点可见性：键盘用户唯一能看见的定位手段 */
:focus-visible {
  outline: 2px solid var(--color-brand-light);
  outline-offset: 2px;
  border-radius: 4px;
}

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 200;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  padding: 8px 14px; border-radius: var(--r-sm);
  transition: top .15s;
}
.skip-link:focus { top: 12px; }

/* ---------- 容器 ---------- */
.shell { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }
.section { padding: 56px 0; }
.section--tight { padding: 36px 0; }
.section + .section { border-top: 1px solid var(--color-border); }
.section-head { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; margin-bottom: 26px; }
.section-head h2 { font-size: 24px; }
.section-head .hint { font-size: 13px; color: var(--color-text-muted); }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 11.5px; font-weight: 800; letter-spacing: .16em;
  text-transform: uppercase; color: var(--color-brand-light);
  margin-bottom: 14px;
}
.eyebrow::before {
  content: ''; width: 18px; height: 2px; background: var(--color-brand-light); border-radius: 2px;
}

/* ---------- 首页 Hero ---------- */
.hero { padding: 68px 0 44px; position: relative; overflow: hidden; }
.hero::after {
  /* 一层极淡的主色光晕，随主题变化；不用图片，避免额外请求 */
  content: ''; position: absolute; inset: -20% -10% auto auto; width: 540px; height: 540px;
  background: radial-gradient(circle at center, color-mix(in srgb, var(--color-brand) 22%, transparent), transparent 68%);
  pointer-events: none; z-index: 0;
}
.hero > * { position: relative; z-index: 1; }
.hero h1 {
  font-size: clamp(30px, 4.4vw, 50px);
  letter-spacing: -.025em;
  max-width: 20ch;
}
.hero h1 em {
  font-style: normal;
  color: var(--color-brand-light);
}
.hero .lead {
  margin: 20px 0 0; font-size: 17.5px; line-height: 1.8;
  color: var(--color-text-secondary); max-width: 62ch;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 28px; }

.stats { display: flex; gap: 40px; flex-wrap: wrap; margin-top: 40px; }
.stat b { display: block; font-size: 30px; font-weight: 800; letter-spacing: -.02em; line-height: 1.1; }
.stat span { font-size: 12.5px; color: var(--color-text-muted); letter-spacing: .02em; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border-radius: 10px;
  font-size: 14px; font-weight: 700; line-height: 1.2;
  border: 1px solid transparent; cursor: pointer;
  background: var(--color-brand); color: #fff;
  transition: background-color .15s, border-color .15s, color .15s, transform .12s;
}
.btn:hover { background: var(--color-brand-light); color: #08201d; text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn--ghost {
  background: transparent; color: var(--color-text-primary);
  border-color: var(--color-border);
}
.btn--ghost:hover {
  background: var(--color-surface); color: var(--color-text-primary);
  border-color: var(--color-brand);
}
.btn--sm { padding: 6px 12px; font-size: 12.5px; border-radius: 8px; }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 18px; }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.card {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--r-lg);
  padding: 22px 22px 20px;
  transition: border-color .18s, transform .18s, box-shadow .18s;
  overflow: hidden;
}
.card::before {
  /* 顶部一条主色细线：8 套主题下自动换色，不用改代码 */
  content: ''; position: absolute; left: 0; right: 0; top: 0; height: 2px;
  background: linear-gradient(to right, var(--color-brand-light), transparent 72%);
  opacity: .8;
}
a.card:hover {
  border-color: var(--color-brand);
  transform: translateY(-2px);
  box-shadow: var(--sh-1);
  text-decoration: none;
}
.card .kicker {
  font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase;
  color: var(--color-text-muted);
}
.card h3 { font-size: 18px; margin: 8px 0 8px; color: var(--color-text-primary); }
.card p { margin: 0; font-size: 14px; line-height: 1.75; color: var(--color-text-secondary); }
.card .meta { margin-top: 14px; display: flex; gap: 8px; flex-wrap: wrap; }

.badge {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 11.5px; font-weight: 700; letter-spacing: .02em;
  padding: 2px 9px; border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-surface-elevated);
  color: var(--color-text-secondary);
}
.badge--live { color: var(--color-brand-light); border-color: color-mix(in srgb, var(--color-brand-light) 45%, var(--color-border)); }
.badge--soon { color: var(--color-text-muted); }
.badge--warn { color: var(--color-accent); border-color: color-mix(in srgb, var(--color-accent) 45%, var(--color-border)); }

/* 语气标签 */
.tag {
  display: inline-block; font-size: 11px; font-weight: 700; letter-spacing: .04em;
  padding: 1px 7px; border-radius: 5px;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  background: var(--color-surface-elevated);
  white-space: nowrap;
}
.tag--formal { color: var(--color-brand-light); border-color: color-mix(in srgb, var(--color-brand-light) 40%, var(--color-border)); }
.tag--friendly { color: var(--color-accent); border-color: color-mix(in srgb, var(--color-accent) 40%, var(--color-border)); }
.tag--hard { color: var(--color-danger); border-color: color-mix(in srgb, var(--color-danger) 40%, var(--color-border)); }

/* ---------- 学习路径 ---------- */
.steps { display: grid; gap: 0; counter-reset: step; }
.step {
  display: grid; grid-template-columns: 46px 1fr; gap: 18px;
  padding: 20px 0; border-bottom: 1px dashed var(--color-border);
  counter-increment: step;
}
.step:last-child { border-bottom: 0; }
.step::before {
  content: counter(step, decimal-leading-zero);
  font-family: var(--font-mono, Consolas, monospace);
  font-size: 13px; font-weight: 700; color: var(--color-brand-light);
  border: 1px solid var(--color-border); border-radius: 8px;
  height: 34px; display: grid; place-items: center;
  background: var(--color-surface-elevated);
}
.step h3 { font-size: 16.5px; margin-bottom: 6px; }
.step p { margin: 0; font-size: 14px; color: var(--color-text-secondary); }
.step .meta { margin-top: 8px; display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }

/* ---------- 内容页：侧栏 + 正文 ---------- */
.content-grid {
  display: grid; grid-template-columns: 226px minmax(0, 1fr);
  gap: 52px; align-items: start; padding: 40px 0 64px;
}
.toc { position: sticky; top: 78px; }
.toc h4 {
  font-size: 11px; letter-spacing: .14em; text-transform: uppercase;
  color: var(--color-text-muted); margin-bottom: 12px; font-weight: 800;
}
.toc a {
  display: block; padding: 5px 0 5px 12px;
  font-size: 13px; color: var(--color-text-secondary);
  border-left: 2px solid var(--color-border);
  margin-left: -2px;
}
.toc a:hover { color: var(--color-text-primary); text-decoration: none; border-left-color: var(--color-brand-light); }
.toc a.active { color: var(--color-brand-light); border-left-color: var(--color-brand-light); font-weight: 700; }
.toc .toc-back { margin-top: 18px; font-size: 12.5px; }

.prose { max-width: 78ch; }
.prose > h2 {
  font-size: 23px; margin: 46px 0 14px; padding-top: 6px;
  scroll-margin-top: 84px;
}
.prose > h2:first-child { margin-top: 0; }
.prose > h2 .num {
  font-family: var(--font-mono, Consolas, monospace);
  font-size: 13px; color: var(--color-brand-light);
  display: block; margin-bottom: 6px; letter-spacing: .1em;
}
.prose > h3 { font-size: 17px; margin: 30px 0 10px; scroll-margin-top: 84px; }
.prose p { margin: 0 0 14px; color: var(--color-text-secondary); font-size: 15.5px; }
.prose strong { color: var(--color-text-primary); font-weight: 700; }
.prose ul, .prose ol { margin: 0 0 16px; padding-left: 22px; color: var(--color-text-secondary); font-size: 15.5px; }
.prose li { margin-bottom: 7px; }
.prose li::marker { color: var(--color-brand-light); }
.prose code {
  font-size: .88em; padding: 1px 5px; border-radius: 5px;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
}
.prose .en, .en { color: var(--color-text-primary); }
.prose .en { font-size: 15.5px; }

/* ---------- 邮件卡片（模拟收件箱条目） ---------- */
.mail {
  border: 1px solid var(--color-border);
  border-radius: var(--r-md);
  background: var(--color-surface);
  overflow: hidden;
  margin: 0 0 18px;
}
.mail-head {
  display: grid; grid-template-columns: 68px minmax(0, 1fr);
  gap: 4px 12px;
  padding: 12px 16px;
  background: var(--color-surface-elevated);
  border-bottom: 1px solid var(--color-border);
  font-size: 12.5px;
}
.mail-head dt { color: var(--color-text-muted); font-weight: 700; letter-spacing: .02em; }
.mail-head dd { margin: 0; color: var(--color-text-primary); overflow-wrap: anywhere; }
.mail-body { padding: 18px 18px 8px; }
.mail-body p { margin: 0 0 12px; font-size: 15px; line-height: 1.8; color: var(--color-text-primary); }
.mail-body .sig { color: var(--color-text-secondary); font-size: 14px; line-height: 1.7; }
.mail-note {
  padding: 10px 16px 14px; font-size: 12.5px; color: var(--color-text-muted);
  border-top: 1px dashed var(--color-border);
}

/* ---------- 对比 / 替换表 ---------- */
.table-wrap { overflow-x: auto; margin: 0 0 18px; border: 1px solid var(--color-border); border-radius: var(--r-md); }
table { width: 100%; border-collapse: collapse; font-size: 14px; background: var(--color-surface); }
th, td { padding: 11px 14px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--color-border); }
th {
  font-size: 11.5px; letter-spacing: .06em; text-transform: uppercase;
  color: var(--color-text-muted); background: var(--color-surface-elevated); font-weight: 800;
  white-space: nowrap;
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: color-mix(in srgb, var(--color-brand) 6%, transparent); }
td .bad { color: var(--color-danger); text-decoration: line-through; text-decoration-thickness: 1px; }
td .good { color: var(--color-text-primary); font-weight: 600; }
td small { display: block; color: var(--color-text-muted); font-size: 12.5px; line-height: 1.6; margin-top: 2px; }

/* ---------- 提示块 ---------- */
.callout {
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-brand-light);
  border-radius: var(--r-md);
  background: color-mix(in srgb, var(--color-brand) 7%, var(--color-surface));
  padding: 14px 16px;
  margin: 0 0 18px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--color-text-secondary);
}
.callout b { color: var(--color-text-primary); }
.callout--warn { border-left-color: var(--color-danger); background: color-mix(in srgb, var(--color-danger) 7%, var(--color-surface)); }
.callout--tip { border-left-color: var(--color-accent); background: color-mix(in srgb, var(--color-accent) 8%, var(--color-surface)); }
.callout .co-title {
  display: block; font-size: 12px; font-weight: 800; letter-spacing: .1em;
  text-transform: uppercase; color: var(--color-text-muted); margin-bottom: 4px;
}

/* ---------- 模板库 ---------- */
.tpl-toolbar {
  display: flex; gap: 10px; flex-wrap: wrap; align-items: center;
  padding: 16px; margin-bottom: 22px;
  border: 1px solid var(--color-border); border-radius: var(--r-md);
  background: var(--color-surface);
}
.tpl-toolbar label { font-size: 12px; font-weight: 700; color: var(--color-text-muted); }
.tpl-toolbar input {
  flex: 1 1 150px; min-width: 120px;
  padding: 7px 10px; font: inherit; font-size: 13px;
  border: 1px solid var(--color-border); border-radius: 8px;
  background: var(--color-bg); color: var(--color-text-primary);
}
.tpl-toolbar input::placeholder { color: var(--color-text-muted); }
.tpl-toolbar input:focus { border-color: var(--color-brand-light); outline: none; }
.tpl-toolbar .tf { display: flex; flex-direction: column; gap: 4px; flex: 1 1 128px; min-width: 108px; }
/* 输入框在 .tf（列向 flex）里必须取消 flex-basis，否则 flex:1 1 150px 会被当成
   高度，输入框被拉成 150px 高（2026-11-10 实测踩到）。 */
.tpl-toolbar .tf input { flex: 0 0 auto; width: 100%; }
.tpl-toolbar .tf label { font-size: 11px; letter-spacing: .02em; }

.tpl {
  border: 1px solid var(--color-border); border-radius: var(--r-md);
  background: var(--color-surface); margin-bottom: 16px; overflow: hidden;
}
.tpl-top {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 13px 16px; border-bottom: 1px solid var(--color-border);
  background: var(--color-surface-elevated);
}
.tpl-top h3 { font-size: 15.5px; margin: 0; flex: 1 1 240px; }
.tpl-top h3 span { font-size: 12px; font-weight: 600; color: var(--color-text-muted); margin-left: 8px; }
.tpl pre {
  margin: 0; padding: 16px;
  font-family: var(--font-sans, system-ui, sans-serif);
  font-size: 14.5px; line-height: 1.85; color: var(--color-text-primary);
  white-space: pre-wrap; overflow-wrap: anywhere;
  max-height: 340px; overflow: auto;
}
.tpl .var-hl { color: var(--color-brand-light); font-weight: 700; }

/* ---------- 句式库 ---------- */
.filters { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }
.chip {
  border: 1px solid var(--color-border); background: var(--color-surface);
  color: var(--color-text-secondary);
  font: inherit; font-size: 12.5px; font-weight: 700;
  padding: 5px 12px; border-radius: 999px; cursor: pointer;
  transition: color .15s, border-color .15s, background-color .15s;
}
.chip:hover { color: var(--color-text-primary); border-color: var(--color-brand-light); }
.chip.on { background: var(--color-brand); color: #fff; border-color: var(--color-brand); }
.chip.on:hover { color: #fff; }

.search-input {
  width: 100%; padding: 10px 14px; margin-bottom: 14px;
  font: inherit; font-size: 14px;
  border: 1px solid var(--color-border); border-radius: 10px;
  background: var(--color-surface); color: var(--color-text-primary);
}
.search-input:focus { border-color: var(--color-brand-light); outline: none; }

.phrase-group { margin-bottom: 26px; }
.phrase-group > h3 {
  font-size: 13px; letter-spacing: .1em; text-transform: uppercase;
  color: var(--color-text-muted); margin: 0 0 10px;
}
.phrase {
  display: grid; grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px 14px; align-items: start;
  padding: 12px 14px; border: 1px solid var(--color-border);
  border-radius: 10px; background: var(--color-surface); margin-bottom: 8px;
}
.phrase:hover { border-color: color-mix(in srgb, var(--color-brand-light) 55%, var(--color-border)); }
.phrase .ph-en { font-size: 15px; color: var(--color-text-primary); line-height: 1.65; }
.phrase .ph-cn { font-size: 13px; color: var(--color-text-muted); margin-top: 3px; }
.phrase .ph-side { display: flex; gap: 6px; align-items: center; }
.icon-btn {
  border: 1px solid var(--color-border); background: var(--color-surface-elevated);
  color: var(--color-text-secondary); border-radius: 7px;
  width: 30px; height: 30px; display: grid; place-items: center;
  cursor: pointer; transition: color .15s, border-color .15s;
}
.icon-btn:hover { color: var(--color-text-primary); border-color: var(--color-brand); }
.icon-btn.on { color: var(--color-accent); border-color: var(--color-accent); }
.empty-state { padding: 30px 0; text-align: center; color: var(--color-text-muted); font-size: 14px; }

/* ---------- 检查清单 ---------- */
.checklist { display: grid; gap: 10px; margin: 0 0 18px; padding: 0; list-style: none; counter-reset: ck; }
.checklist li { counter-increment: ck; }
.check-item {
  display: grid; grid-template-columns: 26px minmax(0, 1fr); gap: 12px; align-items: start;
  padding: 11px 14px; border: 1px solid var(--color-border); border-radius: 10px;
  background: var(--color-surface); cursor: pointer;
  transition: border-color .15s, background-color .15s;
}
.check-item:hover { border-color: color-mix(in srgb, var(--color-brand-light) 50%, var(--color-border)); }
.check-item input { position: absolute; opacity: 0; pointer-events: none; }
.check-item .box {
  width: 20px; height: 20px; margin-top: 1px;
  border: 1.5px solid var(--color-border-light); border-radius: 5px;
  display: grid; place-items: center; transition: background-color .15s, border-color .15s;
}
.check-item .box::after {
  content: ''; width: 5px; height: 9px;
  border: solid #fff; border-width: 0 2px 2px 0;
  transform: rotate(45deg) translateY(-1px) scale(.6); opacity: 0;
  transition: opacity .12s;
}
.check-item input:checked + .box { background: var(--color-brand); border-color: var(--color-brand); }
.check-item input:checked + .box::after { opacity: 1; }
.check-item input:checked ~ .ck-text { color: var(--color-text-muted); text-decoration: line-through; text-decoration-thickness: 1px; }
.check-item input:focus-visible + .box { outline: 2px solid var(--color-brand-light); outline-offset: 2px; }
.ck-text { font-size: 14.5px; color: var(--color-text-primary); line-height: 1.65; }
.ck-text small { display: block; color: var(--color-text-muted); font-size: 12.5px; margin-top: 2px; }

.progress-line {
  height: 6px; border-radius: 999px; background: var(--color-surface-elevated);
  border: 1px solid var(--color-border); overflow: hidden; margin: 0 0 8px;
}
.progress-line i { display: block; height: 100%; width: 0; background: var(--color-brand-light); transition: width .25s; }
.progress-text { font-size: 12.5px; color: var(--color-text-muted); margin: 0 0 18px; }

/* ---------- 自测 ---------- */
.quiz-q {
  border: 1px solid var(--color-border); border-radius: var(--r-md);
  background: var(--color-surface); padding: 18px; margin-bottom: 14px;
}
.quiz-q h3 { font-size: 15.5px; margin: 0 0 4px; }
.quiz-q .q-hint { font-size: 12.5px; color: var(--color-text-muted); margin: 0 0 12px; }
.quiz-q .q-stem {
  font-size: 15px; line-height: 1.8; color: var(--color-text-primary);
  padding: 12px 14px; border-radius: 8px; margin-bottom: 12px;
  background: var(--color-surface-elevated); border: 1px dashed var(--color-border);
}
.opt {
  display: block; width: 100%; text-align: left;
  padding: 10px 14px; margin-bottom: 8px;
  border: 1px solid var(--color-border); border-radius: 8px;
  background: var(--color-bg); color: var(--color-text-primary);
  font: inherit; font-size: 14.5px; line-height: 1.6; cursor: pointer;
  transition: border-color .15s, background-color .15s;
}
.opt:hover { border-color: var(--color-brand-light); }
.opt.right { border-color: var(--color-success); background: color-mix(in srgb, var(--color-success) 14%, var(--color-surface)); }
.opt.wrong { border-color: var(--color-danger); background: color-mix(in srgb, var(--color-danger) 14%, var(--color-surface)); }
.opt:disabled { cursor: default; }
.q-exp {
  margin: 10px 0 0; font-size: 13.5px; line-height: 1.75; color: var(--color-text-secondary);
  border-left: 2px solid var(--color-brand-light); padding-left: 12px;
}
.q-exp[hidden] { display: none; }

.scorebar {
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
  padding: 16px 18px; border: 1px solid var(--color-border); border-radius: var(--r-md);
  background: var(--color-surface); margin-bottom: 22px;
}
.scorebar b { font-size: 26px; letter-spacing: -.02em; }
.scorebar span { font-size: 13px; color: var(--color-text-muted); }

/* ---------- 上一页/下一页 ---------- */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 46px; }
.pager a {
  border: 1px solid var(--color-border); border-radius: var(--r-md);
  padding: 14px 16px; background: var(--color-surface);
  transition: border-color .15s;
}
.pager a:hover { border-color: var(--color-brand); text-decoration: none; }
.pager small { display: block; font-size: 11.5px; color: var(--color-text-muted); letter-spacing: .08em; text-transform: uppercase; }
.pager strong { display: block; font-size: 15px; color: var(--color-text-primary); margin-top: 3px; }
.pager a.next { text-align: right; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .content-grid { grid-template-columns: 1fr; gap: 0; }
  .toc { display: none; }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 720px) {
  .shell { padding: 0 20px; }
  .hero { padding: 44px 0 30px; }
  .section { padding: 40px 0; }
  .grid--3, .grid--2 { grid-template-columns: 1fr; }
  .stats { gap: 26px; }
  .pager { grid-template-columns: 1fr; }
  .pager a.next { text-align: left; }
  .mail-head { grid-template-columns: 58px minmax(0, 1fr); }
}
@media (max-width: 480px) {
  .hero h1 { font-size: 27px; }
  .stat b { font-size: 24px; }
  .tpl-toolbar input { flex: 1 1 100%; }
}

/* 打印：正文页去掉页眉页脚与侧栏，只留内容 */
@media print {
  .topbar, footer, .toc, .pager, .skip-link { display: none !important; }
  body { background: #fff; color: #000; }
  .prose { max-width: none; }
}