/* ============ Hello AI 课程网站 ============ */
/* 设计语言：poolside.ai × runner.now
   米白底 · 常规字重大标题 · 等宽大写标签 · 电光蓝紫强调
   虚线细边框卡片 · 衬线卡片标题 · 锈橙斜体编号 */

@import url('https://fonts.googleapis.com/css2?family=Instrument+Sans:wght@400;500;600&family=Instrument+Serif:ital@0;1&family=Fragment+Mono:ital@0;1&family=Noto+Sans+SC:wght@400;500;700&family=Noto+Serif+SC:wght@500;600&display=swap');

:root {
  --bg: #fbfaf6;
  --bg-soft: #f4f2ea;
  --ink: #0d0d0c;
  --ink-2: #55534c;
  --ink-3: #8d8a80;
  --indigo: #4b4bf7;
  --indigo-deep: #3434d6;
  --green: #4ba12d;
  --rust: #b5532a;
  --dot: #d4d0c4;
  --card: #fefdfa;
  --dark: #131310;
  --dark-text: #e9e6da;
  --sans: 'Instrument Sans', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --serif: 'Instrument Serif', 'Noto Serif SC', 'Songti SC', serif;
  --mono: 'Fragment Mono', 'Cascadia Code', Consolas, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.8;
  font-size: 16px;
}

::selection { background: var(--indigo); color: #fff; }

a { color: var(--ink); text-decoration: none; }

/* ============ 布局：左侧固定导航 ============ */
.shell {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  min-height: 100vh;
}

.sidenav {
  position: sticky;
  top: 0;
  height: 100vh;
  padding: 36px 0 28px 36px;
  display: flex;
  flex-direction: column;
  font-family: var(--mono);
}
.sidenav .logo {
  font-size: 13px;
  letter-spacing: 1px;
  color: var(--ink-3);
  margin-bottom: 34px;
  display: block;
}
.sidenav .logo b { color: var(--ink); font-weight: 400; }
.sidenav .nav-group { display: flex; flex-direction: column; gap: 2px; }
.sidenav .nav-group a {
  font-size: 12px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--ink-2);
  padding: 6px 0;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: color 0.15s;
}
.sidenav .nav-group a:hover { color: var(--indigo); }
.sidenav .nav-group a.active { color: var(--indigo); }
.sidenav .nav-group a.active::before { content: '◆'; font-size: 9px; }
.sidenav .nav-foot { margin-top: auto; font-size: 11px; color: var(--ink-3); line-height: 2; }
.sidenav .nav-foot .who {
  border-top: 1px dotted var(--dot);
  padding-top: 14px;
  margin-top: 14px;
}
.sidenav .nav-foot .who .uname { color: var(--ink); }
.sidenav .nav-foot .who .uid { color: var(--indigo); }
.sidenav .nav-foot a { color: var(--ink-3); text-decoration: underline dotted; }
.sidenav .nav-foot a:hover { color: var(--indigo); }

.main { padding: 0 56px 90px 56px; max-width: 1180px; }

/* ============ 顶部移动端条 ============ */
.mobilebar { display: none; }

/* ============ Hero ============ */
.hero {
  padding: 96px 0 64px;
  position: relative;
}
.hero .kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--indigo);
  margin-bottom: 26px;
  animation: rise 0.7s ease both;
}
.hero h1 {
  font-weight: 400;
  font-size: clamp(40px, 5.6vw, 64px);
  line-height: 1.18;
  letter-spacing: -0.5px;
  max-width: 720px;
  animation: rise 0.7s 0.08s ease both;
}
.hero h1 .serif-it { font-family: var(--serif); font-style: italic; color: var(--indigo); }
.hero .sub {
  margin-top: 24px;
  max-width: 540px;
  font-size: 16.5px;
  color: var(--ink-2);
  animation: rise 0.7s 0.16s ease both;
}
.hero .cta-row {
  display: flex;
  gap: 12px;
  margin-top: 36px;
  animation: rise 0.7s 0.24s ease both;
}
.btn {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.5px;
  padding: 11px 24px;
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.18s;
}
.btn:hover { background: var(--ink); color: var(--bg); text-decoration: none; }
.btn.primary { background: var(--indigo); border-color: var(--indigo); color: #fff; }
.btn.primary:hover { background: var(--indigo-deep); border-color: var(--indigo-deep); }

/* 线框立方体装饰 */
.hero .cubes {
  position: absolute;
  right: 0;
  top: 70px;
  width: 300px;
  height: 280px;
  pointer-events: none;
  animation: rise 1s 0.3s ease both;
}
.hero .cubes svg { width: 100%; height: 100%; }

@keyframes rise {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: none; }
}

/* 数字行 */
.hero .stats {
  display: flex;
  gap: 56px;
  margin-top: 64px;
  border-top: 1px dotted var(--dot);
  padding-top: 28px;
  animation: rise 0.7s 0.32s ease both;
}
.hero .stat .num {
  font-family: var(--serif);
  font-style: italic;
  font-size: 40px;
  line-height: 1.2;
  color: var(--ink);
}
.hero .stat .num em { font-style: italic; color: var(--rust); }
.hero .stat .label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ============ 区块 ============ */
.section { padding: 56px 0 0; }
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 28px;
}
.section-head h2 {
  font-weight: 400;
  font-size: 30px;
  letter-spacing: -0.3px;
}
.section-head .tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ============ 学习路径（poolside 双栏式） ============ */
.path { border-top: 1px dotted var(--dot); }
.path .phase {
  display: grid;
  grid-template-columns: 200px 1fr 240px;
  gap: 32px;
  padding: 26px 0;
  border-bottom: 1px dotted var(--dot);
}
.path .ph-no {
  font-family: var(--serif);
  font-style: italic;
  font-size: 22px;
  color: var(--rust);
}
.path .ph-no span {
  display: block;
  font-family: var(--mono);
  font-style: normal;
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-top: 2px;
}
.path .ph-main h3 { font-weight: 500; font-size: 18px; margin-bottom: 4px; }
.path .ph-main p { font-size: 14.5px; color: var(--ink-2); }
.path .ph-high {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--green);
  line-height: 1.7;
  align-self: center;
}
.path .ph-high::before { content: '→ '; }

/* ============ 章节卡片（runner 虚线网格） ============ */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px dotted var(--dot);
  border-left: 1px dotted var(--dot);
}
.chapter-card {
  display: block;
  border-right: 1px dotted var(--dot);
  border-bottom: 1px dotted var(--dot);
  padding: 26px 28px 22px;
  position: relative;
  transition: background 0.2s;
}
.chapter-card:hover { background: var(--card); text-decoration: none; }
.chapter-card .ch-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 10px;
}
.chapter-card .ch-num {
  font-family: var(--serif);
  font-style: italic;
  font-size: 19px;
  color: var(--rust);
}
.chapter-card .ch-progress {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  color: var(--ink-3);
}
.chapter-card .ch-progress.done { color: var(--green); }
.chapter-card h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 25px;
  line-height: 1.3;
  margin-bottom: 6px;
}
.chapter-card:hover h3 { color: var(--indigo); }
.chapter-card p { font-size: 13px; color: var(--ink-2); line-height: 1.7; }
.chapter-card .ch-bar {
  margin-top: 16px;
  height: 2px;
  background: var(--bg-soft);
}
.chapter-card .ch-bar i {
  display: block;
  height: 100%;
  background: var(--indigo);
  transition: width 0.4s ease;
}

/* ============ 总进度 ============ */
.global-progress {
  display: flex;
  align-items: center;
  gap: 22px;
  padding: 18px 0;
  margin-bottom: 26px;
  border-top: 1px dotted var(--dot);
  border-bottom: 1px dotted var(--dot);
}
.global-progress .gp-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--ink-3);
  white-space: nowrap;
}
.global-progress .gp-bar { flex: 1; height: 3px; background: var(--bg-soft); }
.global-progress .gp-bar i { display: block; height: 100%; background: var(--indigo); transition: width 0.5s ease; }
.global-progress .gp-pct {
  font-family: var(--serif);
  font-style: italic;
  font-size: 26px;
  min-width: 64px;
  text-align: right;
  color: var(--ink);
}

/* ============ 章节阅读页 ============ */
.reader {
  display: grid;
  grid-template-columns: minmax(0, 700px) 200px;
  gap: 64px;
  padding-top: 56px;
}
.reader-body .ch-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--indigo);
}
.reader-body .ch-no-big {
  font-family: var(--serif);
  font-style: italic;
  font-size: 22px;
  color: var(--rust);
  margin-top: 18px;
}
.reader-body h1 {
  font-weight: 400;
  font-size: clamp(34px, 4.5vw, 48px);
  letter-spacing: -0.5px;
  margin: 4px 0 18px;
  line-height: 1.22;
}
.reader-body .ch-intro {
  font-size: 16px;
  color: var(--ink-2);
  border-left: 2px solid var(--indigo);
  padding-left: 18px;
  margin-bottom: 44px;
}
.reader-body h2 {
  font-weight: 500;
  font-size: 23px;
  margin: 52px 0 14px;
  scroll-margin-top: 40px;
  letter-spacing: -0.2px;
}
.reader-body h2::before {
  content: '§';
  font-family: var(--serif);
  font-style: italic;
  color: var(--rust);
  margin-right: 10px;
}
.reader-body h3 { font-weight: 600; font-size: 16px; margin: 26px 0 8px; }
.reader-body p { margin: 12px 0; font-size: 15.5px; }
.reader-body ul, .reader-body ol { margin: 12px 0 12px 20px; }
.reader-body li { margin: 7px 0; font-size: 15.5px; }
.reader-body strong { color: var(--ink); font-weight: 600; }

.reader-body pre {
  background: var(--dark);
  color: var(--dark-text);
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.9;
  padding: 18px 22px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 16px 0;
}
.reader-body code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--bg-soft);
  padding: 2px 6px;
  border-radius: 4px;
}
.reader-body pre code { background: none; padding: 0; }

.reader-body .note, .reader-body .warn {
  border: 1px dotted var(--dot);
  background: var(--card);
  padding: 14px 18px;
  margin: 18px 0;
  font-size: 14.5px;
  border-radius: 8px;
}
.reader-body .note { border-left: 2px solid var(--green); }
.reader-body .warn { border-left: 2px solid var(--rust); }

.reader-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 14px;
}
.reader-body th, .reader-body td {
  border-bottom: 1px dotted var(--dot);
  padding: 9px 12px;
  text-align: left;
}
.reader-body th {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 400;
}

/* 右侧目录 */
.reader-toc {
  position: sticky;
  top: 48px;
  align-self: start;
  font-size: 12.5px;
}
.reader-toc .toc-title {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 12px;
}
.reader-toc a {
  display: block;
  color: var(--ink-2);
  padding: 4px 0 4px 12px;
  border-left: 1px dotted var(--dot);
  line-height: 1.55;
}
.reader-toc a:hover { color: var(--indigo); text-decoration: none; }
.reader-toc a.current { color: var(--indigo); border-left: 1px solid var(--indigo); }
.reader-toc .toc-tasks {
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px dotted var(--dot);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
}
.reader-toc .toc-tasks b { color: var(--indigo); font-weight: 400; }

/* ============ 任务清单 ============ */
.tasks-box {
  margin-top: 60px;
  border: 1px dotted var(--ink-3);
  border-radius: 10px;
  background: var(--card);
  overflow: hidden;
}
.tasks-box .tasks-head {
  padding: 16px 24px 12px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 1px dotted var(--dot);
}
.tasks-box .tasks-head .t-title {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--ink);
}
.tasks-box .tasks-head .t-count {
  font-family: var(--serif);
  font-style: italic;
  font-size: 20px;
  color: var(--rust);
}
.tasks-box ul { list-style: none; padding: 6px 0; }
.tasks-box li { border-bottom: 1px dotted var(--dot); }
.tasks-box li:last-child { border-bottom: none; }
.tasks-box label {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 13px 24px;
  cursor: pointer;
  font-size: 15px;
  transition: background 0.15s;
}
.tasks-box label:hover { background: var(--bg-soft); }
.tasks-box input[type="checkbox"] {
  appearance: none;
  width: 18px; height: 18px;
  min-width: 18px;
  border: 1.5px solid var(--ink-3);
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
  position: relative;
  margin-top: 5px;
  transition: all 0.15s;
}
.tasks-box input[type="checkbox"]:checked { background: var(--indigo); border-color: var(--indigo); }
.tasks-box input[type="checkbox"]:checked::after {
  content: '✓';
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 11px;
}
.tasks-box input:checked + span { color: var(--ink-3); text-decoration: line-through; }
.tasks-box .tasks-done-msg {
  display: none;
  padding: 13px 24px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--green);
  border-top: 1px dotted var(--dot);
}
.tasks-box.all-done .tasks-done-msg { display: block; }
.tasks-box .sync-state {
  padding: 8px 24px 12px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 1px;
  color: var(--ink-3);
}
.tasks-box .sync-state.ok { color: var(--green); }
.tasks-box .sync-state.err { color: var(--rust); }

/* ============ 翻页 ============ */
.pager {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  margin-top: 44px;
}
.pager a {
  flex: 1;
  border: 1px dotted var(--dot);
  border-radius: 10px;
  padding: 16px 20px;
  transition: all 0.15s;
}
.pager a:hover { text-decoration: none; border-color: var(--indigo); background: var(--card); }
.pager a .dir {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 2px;
  color: var(--indigo);
}
.pager a .name { font-family: var(--serif); font-size: 18px; margin-top: 4px; }
.pager a.next { text-align: right; }
.pager .spacer { flex: 1; }

/* ============ 速查 / FAQ ============ */
.page-head { padding: 80px 0 36px; }
.page-head h1 { font-weight: 400; font-size: clamp(36px, 5vw, 54px); letter-spacing: -0.5px; }
.page-head h1 .serif-it { font-family: var(--serif); font-style: italic; color: var(--indigo); }
.page-head p { color: var(--ink-2); margin-top: 12px; max-width: 540px; }
.page-head .mono-note { font-family: var(--mono); font-size: 11px; color: var(--green); letter-spacing: 1px; }

.ref-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px dotted var(--dot);
  border-left: 1px dotted var(--dot);
}
.ref-card {
  border-right: 1px dotted var(--dot);
  border-bottom: 1px dotted var(--dot);
  padding: 26px 28px;
}
.ref-card h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 23px;
  margin-bottom: 14px;
}
.ref-card h3 .no { font-style: italic; color: var(--rust); font-size: 17px; margin-right: 10px; }
.ref-card table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.ref-card td, .ref-card th { padding: 7px 8px 7px 0; border-bottom: 1px dotted var(--dot); vertical-align: top; }
.ref-card th { font-family: var(--mono); font-size: 10.5px; letter-spacing: 1px; text-transform: uppercase; color: var(--ink-3); text-align: left; font-weight: 400; }
.ref-card td:first-child { font-weight: 500; white-space: nowrap; padding-right: 18px; }
.ref-card .mono { font-family: var(--mono); font-size: 12px; }
.ref-card pre {
  background: var(--dark);
  color: var(--dark-text);
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.9;
  padding: 14px 18px;
  border-radius: 8px;
  overflow-x: auto;
}
.ref-card .small-note { font-size: 13px; color: var(--ink-2); margin-top: 10px; }

.faq-list { counter-reset: faq; }
.faq-item { border-bottom: 1px dotted var(--dot); }
.faq-item:first-of-type { border-top: 1px dotted var(--dot); }
.faq-item summary {
  cursor: pointer;
  padding: 20px 4px;
  font-size: 17px;
  font-weight: 500;
  list-style: none;
  display: flex;
  align-items: baseline;
  gap: 16px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::before {
  content: counter(faq, decimal-leading-zero);
  counter-increment: faq;
  font-family: var(--serif);
  font-style: italic;
  font-size: 15px;
  color: var(--rust);
  min-width: 26px;
}
.faq-item .faq-a { padding: 0 4px 22px 42px; color: var(--ink-2); font-size: 15px; max-width: 640px; }
.faq-item .faq-a a { color: var(--indigo); text-decoration: underline dotted; }

/* ============ 登录页 ============ */
.auth-wrap {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 40px 20px;
  position: relative;
}
.auth-card {
  width: 100%;
  max-width: 420px;
  border: 1px dotted var(--ink-3);
  border-radius: 12px;
  background: var(--card);
  padding: 40px 40px 34px;
  position: relative;
  z-index: 2;
}
.auth-card .logo-line {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--indigo);
  text-transform: uppercase;
  margin-bottom: 18px;
}
.auth-card h1 { font-weight: 400; font-size: 32px; letter-spacing: -0.3px; margin-bottom: 8px; }
.auth-card h1 .serif-it { font-family: var(--serif); font-style: italic; color: var(--indigo); }
.auth-card .hint { font-size: 14px; color: var(--ink-2); margin-bottom: 26px; }
.auth-card label.fld {
  display: block;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 8px;
}
.auth-card input[type="text"], .auth-card input[type="password"] {
  width: 100%;
  font-family: var(--mono);
  font-size: 16px;
  letter-spacing: 1px;
  padding: 12px 16px;
  border: 1px solid var(--dot);
  border-radius: 8px;
  background: var(--bg);
  color: var(--ink);
  outline: none;
  transition: border-color 0.15s;
}
.auth-card input:focus { border-color: var(--indigo); }
.auth-card .btn { width: 100%; justify-content: center; margin-top: 18px; padding: 13px; font-size: 14px; }
.auth-card .err-msg {
  display: none;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--rust);
  margin-top: 12px;
}
.auth-card .alt {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px dotted var(--dot);
  font-size: 13px;
  color: var(--ink-3);
  display: flex;
  justify-content: space-between;
}
.auth-card .alt a { color: var(--ink-2); text-decoration: underline dotted; }
.auth-card .alt a:hover { color: var(--indigo); }
.auth-cubes { position: absolute; width: 260px; opacity: 0.8; pointer-events: none; }
.auth-cubes.tl { top: 8%; left: 8%; }
.auth-cubes.br { bottom: 8%; right: 6%; transform: rotate(180deg); }

/* ============ 教师端 ============ */
.t-toolbar {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 26px;
}
.t-toolbar input[type="text"] {
  font-family: var(--mono);
  font-size: 14px;
  padding: 10px 16px;
  border: 1px solid var(--dot);
  border-radius: 999px;
  background: var(--card);
  outline: none;
  width: 200px;
}
.t-toolbar input:focus { border-color: var(--indigo); }
.t-toolbar .btn { padding: 10px 20px; }
.t-toolbar .spacer { flex: 1; }
.t-toolbar .t-stat { font-family: var(--mono); font-size: 12px; color: var(--ink-3); }
.t-toolbar .t-stat b { color: var(--indigo); font-weight: 400; }

.t-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.t-table th {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 400;
  text-align: left;
  padding: 10px 10px;
  border-bottom: 1px solid var(--ink);
}
.t-table td { padding: 13px 10px; border-bottom: 1px dotted var(--dot); vertical-align: middle; }
.t-table .stu-name { font-weight: 500; white-space: nowrap; }
.t-table .stu-id {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--indigo);
  cursor: pointer;
  white-space: nowrap;
}
.t-table .stu-id:hover::after { content: ' ⧉'; color: var(--ink-3); }
.t-table .ch-cells { display: flex; gap: 4px; }
.t-table .ch-cell {
  width: 26px; height: 18px;
  border-radius: 4px;
  background: var(--bg-soft);
  position: relative;
  overflow: hidden;
}
.t-table .ch-cell i {
  position: absolute;
  left: 0; top: 0; bottom: 0;
  background: var(--indigo);
  opacity: 0.85;
}
.t-table .ch-cell.full { outline: 1px solid var(--green); }
.t-table .ch-cell.full i { background: var(--green); }
.t-table .pct {
  font-family: var(--serif);
  font-style: italic;
  font-size: 19px;
  color: var(--ink);
  white-space: nowrap;
}
.t-table .last-seen { font-family: var(--mono); font-size: 11px; color: var(--ink-3); white-space: nowrap; }
.t-table .del-btn {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-3);
  background: none;
  border: none;
  cursor: pointer;
  text-decoration: underline dotted;
}
.t-table .del-btn:hover { color: var(--rust); }
.t-empty {
  padding: 60px 0;
  text-align: center;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--ink-3);
}

/* ============ 页脚 ============ */
footer {
  border-top: 1px dotted var(--dot);
  margin-top: 90px;
  padding: 30px 0;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.5px;
  color: var(--ink-3);
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
footer em { font-style: normal; color: var(--indigo); }

/* ============ 响应式 ============ */
@media (max-width: 980px) {
  .shell { grid-template-columns: 1fr; }
  .sidenav { display: none; }
  .mobilebar {
    display: flex;
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(251, 250, 246, 0.94);
    backdrop-filter: blur(8px);
    border-bottom: 1px dotted var(--dot);
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    height: 54px;
    font-family: var(--mono);
  }
  .mobilebar .logo { font-size: 13px; color: var(--ink); }
  .mobilebar nav { display: flex; gap: 14px; }
  .mobilebar nav a { font-size: 11px; letter-spacing: 1px; text-transform: uppercase; color: var(--ink-2); }
  .mobilebar nav a.active { color: var(--indigo); }
  .main { padding: 0 22px 70px; }
  .hero { padding-top: 56px; }
  .hero .cubes { display: none; }
  .path .phase { grid-template-columns: 1fr; gap: 8px; }
  .chapters-grid { grid-template-columns: 1fr; }
  .ref-grid { grid-template-columns: 1fr; }
  .reader { grid-template-columns: 1fr; gap: 0; }
  .reader-toc { display: none; }
  .hero .stats { flex-wrap: wrap; gap: 28px; }
  .t-table .ch-cells { flex-wrap: wrap; }
  .t-table .last-seen { display: none; }
}