/* ==========================================================================
   秋霞视频 · 全站样式
   分组：base / layout / components / pages / responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. base
   -------------------------------------------------------------------------- */

:root {
  --bg: #0a0c0e;
  --panel: #14181c;
  --panel-2: #181d22;
  --line: #222a30;
  --line-soft: #1b2228;
  --text: #e8edf1;
  --text-2: #9aa6af;
  --text-3: #6f7b84;
  --accent: #e5484d;
  --accent-dark: #c33a3f;
  --ready: #3fb950;
  --warn: #d9a441;
  --radius: 6px;
  --radius-sm: 4px;
  --shell: 1180px;
  --read: 760px;
  --header-h: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

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

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

body.site-body {
  margin: 0;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

dl,
dd,
dt,
figure,
figcaption {
  margin: 0;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

a:hover {
  color: var(--accent);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

strong {
  color: var(--text);
  font-weight: 700;
}

/* --------------------------------------------------------------------------
   2. layout · 全站骨架
   -------------------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: rgba(10, 12, 14, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: 100%;
  max-width: var(--shell);
  height: var(--header-h);
  margin: 0 auto;
  padding: 0 24px;
}

/* 品牌标识 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  color: var(--text);
}

.brand:hover {
  color: var(--text);
}

.brand-mark {
  position: relative;
  display: inline-block;
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  border: 2px solid var(--accent);
  border-radius: var(--radius-sm);
}

.brand-mark::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  transform: translate(-38%, -50%);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  border-left: 8px solid var(--accent);
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
}

.brand-slogan {
  padding-left: 12px;
  border-left: 1px solid var(--line);
  color: var(--text-3);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.2;
}

/* 主导航 */
.site-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: flex-end;
}

.main-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav a {
  display: inline-flex;
  align-items: center;
  height: 40px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px;
  white-space: nowrap;
}

.main-nav a:hover {
  color: var(--text);
  background-color: var(--panel);
}

.main-nav a.is-current {
  color: var(--text);
  font-weight: 700;
  background-color: var(--panel);
  box-shadow: inset 0 -2px 0 var(--accent);
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background-color: var(--panel);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--text);
  border-radius: 1px;
}

/* 移动端抽屉 */
.mobile-nav {
  display: none;
}

.mobile-nav[hidden] {
  display: none;
}

/* 主内容 */
.site-main {
  display: block;
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px 72px;
}

.inner-main {
  padding-top: 20px;
}

/* 页脚 */
.site-footer {
  border-top: 1px solid var(--line);
  background-color: #080a0c;
}

.footer-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  width: 100%;
  max-width: var(--shell);
  min-height: 68px;
  margin: 0 auto;
  padding: 14px 24px;
}

.footer-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-shrink: 0;
}

.footer-brand .brand-name {
  font-size: 15px;
}

.footer-slogan {
  color: var(--text-3);
  font-size: 12px;
}

.footer-nav {
  flex: 1 1 auto;
}

.footer-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  justify-content: center;
}

.footer-nav a {
  display: inline-block;
  padding: 6px 0;
  color: var(--text-2);
  font-size: 13px;
}

.footer-nav a:hover {
  color: var(--accent);
}

.back-top {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 13px;
  white-space: nowrap;
}

.back-top:hover {
  color: var(--text);
  border-color: var(--text-3);
  background-color: var(--panel);
}

.footer-copy {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px 22px;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   3. components · 通用组件
   -------------------------------------------------------------------------- */

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  text-align: center;
}

.btn-primary {
  background-color: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background-color: var(--accent-dark);
  border-color: var(--accent-dark);
  color: #fff;
}

.btn-ghost {
  background-color: transparent;
  border-color: var(--line);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: var(--text-3);
  background-color: var(--panel);
  color: var(--text);
}

/* 卡片内链 */
.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
}

.card-link::after {
  content: "→";
  font-size: 14px;
  transition: transform 0.18s ease;
}

.card-link:hover {
  color: #ff6b6f;
}

.card-link:hover::after {
  transform: translateX(3px);
}

/* 区块标题 */
.section-title {
  font-size: 24px;
  line-height: 1.35;
}

.section-desc {
  margin-top: 8px;
  max-width: 720px;
  color: var(--text-2);
  font-size: 15px;
}

.section-head {
  margin-bottom: 22px;
}

.section-note {
  margin-bottom: 18px;
  color: var(--text-2);
  font-size: 15px;
}

.section-intro {
  margin-bottom: 18px;
  max-width: 720px;
  color: var(--text-2);
  font-size: 15px;
}

/* 图片与字幕条 */
.media-caption,
.caption-bar,
.page-hero-media figcaption,
.page-hero-figure figcaption,
.prep-overview-figure figcaption,
.fields-figure figcaption {
  display: block;
  padding: 8px 12px;
  background-color: #0d1114;
  border-top: 1px solid var(--line-soft);
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.55;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  padding: 4px 0 14px;
  color: var(--text-3);
  font-size: 13px;
}

.breadcrumb a {
  color: var(--text-2);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.breadcrumb-sep {
  color: var(--text-3);
}

.breadcrumb-current {
  color: var(--text-2);
}

/* 页标题区 */
.page-header {
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 26px;
}

.page-title {
  font-size: 34px;
  line-height: 1.3;
  color: var(--text);
  font-weight: 700;
}

/* 内页首屏条 */
.page-hero {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
  margin-bottom: 32px;
}

.page-hero-text {
  padding: 24px;
}

.page-hero-inner {
  padding: 24px;
}

.eyebrow,
.page-eyebrow,
.page-kicker {
  margin-bottom: 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.page-lead {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 640px;
}

.page-hero-lead {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}

.page-tags,
.page-hero-tags,
.page-meta-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.page-tags li,
.page-hero-tags li,
.page-meta-tags li,
.page-tags .tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background-color: #0f1316;
  color: var(--text-2);
  font-size: 12px;
  letter-spacing: 0.02em;
}

.page-hero-media,
.page-hero-figure {
  display: block;
  border-top: 1px solid var(--line);
  background-color: #0d1114;
}

.page-hero-media img,
.page-hero-figure img {
  width: 100%;
  height: 100%;
  max-height: 340px;
  object-fit: cover;
}

/* 内页双栏（主内容在前，aside 在后） */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 36px;
  align-items: start;
}

.page-content {
  min-width: 0;
}

.page-aside {
  min-width: 0;
  position: sticky;
  top: calc(var(--header-h) + 16px);
}

.aside-block {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.aside-block + .aside-block {
  margin-top: 16px;
}

.aside-block h2 {
  font-size: 18px;
  margin-bottom: 12px;
}

.aside-links {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.aside-links li {
  border-bottom: 1px solid var(--line-soft);
}

.aside-links li:last-child {
  border-bottom: none;
}

.aside-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 44px;
  color: var(--text-2);
  font-size: 14px;
}

.aside-links a::after {
  content: "→";
  color: var(--text-3);
  font-size: 13px;
}

.aside-links a:hover {
  color: var(--accent);
}

.aside-links span {
  display: block;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.6;
}

/* 相关链接横条 */
.related-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 16px;
  margin-top: 32px;
  padding: 16px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.related-links-label {
  color: var(--text-3);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.related-links-item {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--text-2);
  font-size: 14px;
  border-bottom: 1px dashed var(--line);
}

.related-links-item:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* 跳转链接（无障碍） */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background-color: var(--accent);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
}

.skip-link:focus {
  top: 10px;
  color: #fff;
}

/* --------------------------------------------------------------------------
   4. pages · 首页
   -------------------------------------------------------------------------- */

.home-main {
  padding-top: 28px;
}

/* 首屏 */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 520px);
  gap: 40px;
  align-items: center;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  min-width: 0;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.hero-eyebrow::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 2px;
  background-color: var(--accent);
}

.hero h1 {
  font-size: 42px;
  line-height: 1.25;
  letter-spacing: 0;
}

.hero-lead {
  margin-top: 16px;
  max-width: 520px;
  color: var(--text-2);
  font-size: 16px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.hero-media {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.hero-media img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

/* 三选择维度条 */
.choose-strip {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.choose-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 26px;
}

.choose-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.choose-card:hover {
  border-color: #33404a;
  background-color: var(--panel-2);
}

.choose-card h3 {
  font-size: 18px;
}

.choose-card p {
  flex: 1 1 auto;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

/* 频道结构状态带 */
.status-band {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.status-head {
  margin-bottom: 22px;
}

.status-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
}

.status-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "dot name"
    "note note"
    "link link";
  gap: 6px 8px;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.status-dot {
  grid-area: dot;
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--text-3);
}

.status-dot.is-ready {
  background-color: var(--ready);
  box-shadow: 0 0 0 3px rgba(63, 185, 80, 0.14);
}

.status-dot.is-pending {
  background-color: var(--warn);
  box-shadow: 0 0 0 3px rgba(217, 164, 65, 0.14);
}

.status-name {
  grid-area: name;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.status-note {
  grid-area: note;
  color: var(--text-3);
  font-size: 12px;
  line-height: 1.6;
}

.status-item a {
  grid-area: link;
  align-self: end;
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
}

.status-item a:hover {
  color: #ff6b6f;
}

/* 棋盘图文交替 */
.checkerboard {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.checkerboard > .section-title,
.checkerboard > .section-desc {
  margin-bottom: 0;
}

.checker-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 36px;
  align-items: center;
  margin-top: 30px;
  padding-top: 30px;
  border-top: 1px solid var(--line-soft);
}

.checker-row:first-of-type {
  border-top: none;
  padding-top: 0;
}

.checker-text {
  min-width: 0;
}

.checker-text h3 {
  font-size: 22px;
  margin-bottom: 10px;
}

.checker-text p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}

.checker-list {
  margin: 16px 0 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.checker-list li {
  position: relative;
  padding-left: 18px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.checker-list li::before {
  content: "";
  position: absolute;
  top: 0.68em;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 1px;
  background-color: var(--accent);
}

.checker-media {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.checker-media img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.checker-row.is-reversed .checker-media {
  order: -1;
}

/* 专题片单预览 */
.topic-preview {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.topic-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.topic-item {
  display: grid;
  grid-template-columns: 148px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.topic-item:hover {
  border-color: #33404a;
  background-color: var(--panel-2);
}

.topic-cover {
  min-width: 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background-color: #0d1114;
}

.topic-cover img {
  width: 100%;
  height: 92px;
  object-fit: cover;
}

.topic-body {
  min-width: 0;
}

.topic-tag {
  display: inline-block;
  margin-bottom: 6px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.topic-body h3 {
  font-size: 17px;
  margin-bottom: 4px;
}

.topic-body p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.topic-order {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  margin-top: 8px;
  padding: 0 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-3);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.topic-item > .card-link {
  align-self: center;
  white-space: nowrap;
}

/* 内容观察摘录 */
.notes-preview {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.notes-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.note-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.note-card:hover {
  border-color: #33404a;
}

.note-thumb {
  background-color: #0d1114;
}

.note-thumb img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.note-body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  padding: 20px;
}

.note-body h3 {
  font-size: 18px;
}

.note-body p {
  flex: 1 1 auto;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

/* 观看准备清单 */
.prep-preview {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.prep-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-bottom: 22px;
}

.prep-step {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.prep-step .step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background-color: rgba(229, 72, 77, 0.14);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
}

.prep-step h3 {
  font-size: 17px;
}

.prep-step p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.prep-step .step-limit {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  color: var(--warn);
  font-size: 12px;
  line-height: 1.6;
}

/* 常见疑问预览 */
.faq-preview {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.faq-preview-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.faq-preview-item {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 56px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.faq-preview-item:hover {
  border-color: #33404a;
  background-color: var(--panel-2);
  color: var(--text);
}

.faq-group {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  padding: 0 8px;
  border-radius: var(--radius-sm);
  background-color: rgba(229, 72, 77, 0.12);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
}

.faq-question {
  flex: 1 1 auto;
  min-width: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.5;
}

.faq-preview-item::after {
  content: "→";
  flex-shrink: 0;
  color: var(--text-3);
}

/* 参与说明条 */
.join-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  margin-top: 44px;
  padding: 26px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.join-text {
  min-width: 0;
}

.join-text h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.join-text p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.join-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  flex-shrink: 0;
}

/* --------------------------------------------------------------------------
   4. pages · 频道图谱
   -------------------------------------------------------------------------- */

.page-channel-map .page-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  align-items: stretch;
}

.page-channel-map .page-hero-media {
  border-top: none;
  border-left: 1px solid var(--line);
}

.page-channel-map .page-hero-media img {
  height: 100%;
  max-height: none;
  min-height: 220px;
}

.channel-overview {
  margin-bottom: 34px;
}

.channel-overview h2 {
  font-size: 22px;
  margin-bottom: 12px;
}

.channel-overview > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 720px;
}

.overview-points {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.overview-points li {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.overview-points strong {
  display: block;
  margin-bottom: 4px;
  color: var(--text);
  font-size: 15px;
}

.channel-groups h2 {
  font-size: 22px;
  margin-bottom: 8px;
}

.channel-group {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.group-head {
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
  background-color: #101418;
}

.group-head h3 {
  font-size: 18px;
  margin-bottom: 4px;
}

.group-head p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.channel-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.channel-item {
  min-width: 0;
  padding: 18px 20px;
  border-left: 1px solid var(--line-soft);
}

.channel-item:first-child {
  border-left: none;
}

.channel-label {
  display: inline-flex;
  align-items: center;
  min-height: 24px;
  margin-bottom: 8px;
  padding: 0 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 13px;
  font-weight: 700;
}

.channel-fit {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.channel-topic {
  display: block;
  margin-top: 10px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
}

.channel-method {
  margin-top: 34px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.channel-method h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.channel-method > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 720px;
}

.method-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 20px;
  counter-reset: method;
}

.method-steps li {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  counter-increment: method;
}

.method-steps li::before {
  content: counter(method, decimal-leading-zero);
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}

.method-steps h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.method-steps p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.boundary-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.boundary-list li h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.boundary-list li p {
  color: var(--text-2);
  font-size: 13px;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   4. pages · 专题片单
   -------------------------------------------------------------------------- */

.page-topic-list .page-header {
  margin-bottom: 22px;
}

.page-topic-list .page-hero {
  padding: 24px;
}

.page-topic-list .page-hero-inner {
  padding: 0;
}

.topic-intro {
  margin-bottom: 30px;
}

.topic-intro h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.topic-intro > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 760px;
}

.topic-intro-tips {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.topic-intro-tips li {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.topic-intro-tips strong {
  display: block;
  margin-bottom: 4px;
  color: var(--text);
  font-size: 15px;
}

.topic-entries > .section-title {
  margin-bottom: 18px;
}

.topic-entry {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 0;
  margin-bottom: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.topic-entry-media {
  min-width: 0;
  display: flex;
  flex-direction: column;
  background-color: #0d1114;
}

.topic-entry-media img {
  width: 100%;
  height: 100%;
  min-height: 260px;
  object-fit: cover;
}

.topic-entry-media .caption-bar {
  margin-top: auto;
}

.topic-entry-body {
  min-width: 0;
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.topic-index {
  margin-bottom: 8px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.topic-entry-body h3 {
  font-size: 21px;
  margin-bottom: 8px;
}

.topic-direction {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.topic-item-list {
  width: 100%;
  margin: 14px 0;
  padding: 12px 14px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
  background-color: #101418;
  counter-reset: topicitem;
}

.topic-item-list li {
  position: relative;
  padding: 6px 0 6px 30px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
  counter-increment: topicitem;
}

.topic-item-list li::before {
  content: counter(topicitem, decimal-leading-zero);
  position: absolute;
  top: 6px;
  left: 0;
  color: var(--text-3);
  font-family: var(--font-mono);
  font-size: 12px;
}

.topic-order-tag {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  margin-bottom: 12px;
  padding: 0 10px;
  border: 1px solid rgba(217, 164, 65, 0.4);
  border-radius: var(--radius-sm);
  color: var(--warn);
  font-size: 12px;
}

.topic-entry-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 40px;
  margin-top: auto;
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
}

.topic-entry-link:hover {
  color: #ff6b6f;
}

.topic-entry-right .topic-entry-media {
  order: 2;
  border-left: 1px solid var(--line);
}

.topic-entry-right .topic-entry-body {
  order: 1;
}

.topic-entry-left .topic-entry-media {
  border-right: 1px solid var(--line);
}

.reading-order {
  margin-top: 34px;
  padding-top: 26px;
  border-top: 1px solid var(--line);
}

.reading-order h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.reading-order > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 720px;
}

.reading-order-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 20px;
}

.reading-order-steps > li {
  display: flex;
  gap: 12px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.reading-order-steps .step-num {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background-color: rgba(229, 72, 77, 0.14);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}

.reading-order-steps .step-body {
  min-width: 0;
}

.reading-order-steps h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.reading-order-steps p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.reading-order-steps .step-limit {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed var(--line);
  color: var(--warn);
  font-size: 12px;
}

.related-entry {
  margin-top: 34px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.related-entry h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.related-entry > p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.related-entry-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.related-entry-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px;
}

.related-entry-links a:hover {
  color: var(--text);
  border-color: var(--text-3);
  background-color: var(--panel-2);
}

/* --------------------------------------------------------------------------
   4. pages · 观看准备
   -------------------------------------------------------------------------- */

.page-viewing-prep .page-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  align-items: stretch;
}

.page-viewing-prep .page-hero-figure {
  border-top: none;
  border-left: 1px solid var(--line);
}

.page-viewing-prep .page-hero-figure img {
  height: 100%;
  max-height: none;
  min-height: 220px;
}

.prep-overview {
  margin-bottom: 28px;
}

.prep-overview h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.prep-overview > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 760px;
}

.prep-overview-figure {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.prep-overview-figure img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.prep-anchor-bar {
  position: sticky;
  top: var(--header-h);
  z-index: 30;
  margin-bottom: 28px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background-color: rgba(10, 12, 14, 0.96);
}

.prep-anchor-bar ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.prep-anchor-bar a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background-color: var(--panel);
  color: var(--text-2);
  font-size: 13px;
}

.prep-anchor-bar a:hover {
  color: var(--text);
  border-color: var(--accent);
}

.prep-group {
  margin-bottom: 32px;
  padding-top: 4px;
}

.prep-group h2 {
  font-size: 22px;
  margin-bottom: 8px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.prep-group-lead {
  margin-bottom: 16px;
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
  max-width: 760px;
}

.prep-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.prep-item {
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.prep-item dt {
  margin-bottom: 10px;
  color: var(--text);
  font-size: 16px;
  font-weight: 700;
}

.prep-item dd {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 22px;
}

.prep-item dd p {
  min-width: 0;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.prep-label {
  display: inline-block;
  margin-right: 8px;
  padding: 0 6px;
  border-radius: 2px;
  background-color: #1d252b;
  color: var(--text-3);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.prep-limits {
  margin-bottom: 28px;
  padding: 20px;
  border: 1px solid rgba(217, 164, 65, 0.32);
  border-left: 3px solid var(--warn);
  border-radius: var(--radius);
  background-color: rgba(217, 164, 65, 0.06);
}

.prep-limits h2 {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--warn);
}

.prep-limits p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.8;
}

.prep-related {
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.prep-related h2 {
  font-size: 20px;
  margin-bottom: 14px;
}

.prep-related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.prep-related-list a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px;
}

.prep-related-list a:hover {
  color: var(--text);
  border-color: var(--text-3);
  background-color: var(--panel);
}

/* --------------------------------------------------------------------------
   4. pages · 内容观察
   -------------------------------------------------------------------------- */

.page-content-notes .page-hero {
  padding: 24px;
}

.page-content-notes .page-hero-inner {
  padding: 0;
}

.page-content-notes .page-layout {
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 40px;
}

.notes-article {
  min-width: 0;
  max-width: var(--read);
}

.notes-section {
  margin-bottom: 30px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.notes-section:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.notes-section h2 {
  font-size: 22px;
  margin-bottom: 12px;
}

.notes-conclusion {
  width: 100%;
  max-width: none;
  padding: 16px 18px;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background-color: var(--panel);
  color: var(--text);
  font-size: 16px;
  line-height: 1.8;
}

.conclusion-points {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 16px;
}

.conclusion-points li {
  position: relative;
  width: 100%;
  padding-left: 20px;
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}

.conclusion-points li::before {
  content: "";
  position: absolute;
  top: 0.72em;
  left: 0;
  width: 8px;
  height: 2px;
  background-color: var(--accent);
}

.evidence-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.evidence-list li {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.evidence-list li > strong,
.evidence-list li > span:first-child {
  color: var(--text);
  font-size: 14px;
  font-weight: 700;
}

.evidence-list li p {
  min-width: 0;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.evidence-list li a {
  color: var(--accent);
  font-size: 14px;
  font-weight: 600;
}

.notes-section > p {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.85;
}

.notes-section > p + p {
  margin-top: 12px;
}

.notes-figure {
  margin: 18px 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.notes-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.notes-limits {
  padding: 20px;
  border: 1px solid rgba(217, 164, 65, 0.32);
  border-radius: var(--radius);
  background-color: rgba(217, 164, 65, 0.06);
}

.notes-limits h2 {
  color: var(--warn);
}

.notes-aside {
  min-width: 0;
  position: sticky;
  top: calc(var(--header-h) + 16px);
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.notes-aside h2 {
  font-size: 18px;
  margin-bottom: 10px;
}

.aside-intro {
  margin-bottom: 14px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.aside-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 44px;
  color: var(--text);
  font-size: 14px;
  border-bottom: 1px solid var(--line-soft);
}

.aside-links li:last-child a {
  border-bottom: none;
}

.aside-links a:hover {
  color: var(--accent);
}

.aside-note {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.aside-note p {
  color: var(--text-3);
  font-size: 13px;
  line-height: 1.7;
}

.aside-note a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  margin-top: 6px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   4. pages · 常见疑问
   -------------------------------------------------------------------------- */

.page-faq .page-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  align-items: stretch;
}

.page-faq .page-hero-media {
  border-top: none;
  border-left: 1px solid var(--line);
}

.page-faq .page-hero-media img {
  height: 100%;
  max-height: none;
  min-height: 200px;
}

.faq-cat-nav {
  margin-bottom: 28px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.faq-cat-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.faq-cat-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background-color: var(--panel);
  color: var(--text-2);
  font-size: 13px;
}

.faq-cat-nav a:hover {
  color: var(--text);
  border-color: var(--accent);
}

.faq-section {
  margin-bottom: 32px;
  padding-top: 4px;
}

.faq-section h2 {
  font-size: 22px;
  margin-bottom: 8px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.faq-section .section-intro {
  margin-bottom: 16px;
}

.faq-item {
  margin-bottom: 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.faq-item[open] {
  border-color: #33404a;
}

.faq-item summary {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 52px;
  padding: 14px 48px 14px 18px;
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  cursor: pointer;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 16px;
  transform: translateY(-50%);
  width: 24px;
  height: 24px;
  line-height: 22px;
  text-align: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 16px;
  font-weight: 400;
}

.faq-item[open] summary::after {
  content: "−";
  border-color: var(--accent);
  color: var(--accent);
}

.faq-item summary:hover {
  background-color: var(--panel-2);
}

.faq-answer {
  padding: 4px 18px 18px;
  border-top: 1px solid var(--line-soft);
}

.faq-answer p {
  margin-top: 12px;
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.85;
}

.faq-answer a {
  color: var(--accent);
  font-weight: 600;
}

.related-reading {
  margin-top: 34px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.related-reading h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.related-reading > p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.related-list a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--text-2);
  font-size: 14px;
}

.related-list a:hover {
  color: var(--text);
  border-color: var(--text-3);
  background-color: var(--panel-2);
}

/* --------------------------------------------------------------------------
   4. pages · 参与说明
   -------------------------------------------------------------------------- */

.page-participation .page-layout {
  display: block;
}

.page-head {
  margin-bottom: 30px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.page-head .page-lead {
  max-width: 820px;
}

.page-head .page-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.page-head .tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background-color: #0f1316;
  color: var(--text-2);
  font-size: 12px;
}

.scope-section,
.exclude-section,
.basis-section,
.boundary-section,
.related-section {
  margin-bottom: 30px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.scope-section h2,
.exclude-section h2,
.fields-section h2,
.basis-section h2,
.boundary-section h2,
.related-section h2 {
  font-size: 22px;
  margin-bottom: 10px;
}

.scope-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.scope-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.scope-card h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.scope-card p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.scope-card ul {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.scope-card li {
  position: relative;
  padding-left: 16px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.scope-card li::before {
  content: "";
  position: absolute;
  top: 0.7em;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 1px;
  background-color: var(--accent);
}

.exclude-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  counter-reset: exclude;
}

.exclude-list li {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  counter-increment: exclude;
}

.exclude-list li::before {
  content: "× " counter(exclude, decimal-leading-zero);
  display: block;
  margin-bottom: 6px;
  color: var(--warn);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}

.exclude-list h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.exclude-list p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.fields-section {
  margin-bottom: 30px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
}

.fields-figure {
  margin: 16px 0 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.fields-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.field-list {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  overflow: hidden;
}

.field-list dt {
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  background-color: #101418;
  color: var(--text);
  font-size: 15px;
  font-weight: 700;
}

.field-list dd {
  min-width: 0;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.75;
}

.field-list dt:nth-last-of-type(1),
.field-list dd:nth-last-of-type(1) {
  border-bottom: none;
}

.basis-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.basis-list li {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.basis-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  margin-bottom: 10px;
  border-radius: var(--radius-sm);
  background-color: rgba(229, 72, 77, 0.14);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
}

.basis-list h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.basis-list p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.boundary-section .boundary-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.boundary-section .boundary-list li {
  padding: 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--warn);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.boundary-section .boundary-list h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.boundary-section .boundary-list p {
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.related-section {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.related-section .related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
  padding: 0;
  border: none;
  background-color: transparent;
}

.related-section .related-links li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1 1 220px;
  min-width: 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
}

.related-section .related-links a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
}

.related-section .related-links a:hover {
  color: var(--accent);
}

.related-section .related-links span {
  color: var(--text-3);
  font-size: 13px;
  line-height: 1.6;
}

/* --------------------------------------------------------------------------
   4. pages · 404
   -------------------------------------------------------------------------- */

.error-main {
  padding-top: 64px;
  padding-bottom: 88px;
}

.error-block {
  max-width: 720px;
  margin: 0 auto;
  padding: 36px 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  text-align: center;
}

.error-code {
  margin-bottom: 10px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 56px;
  font-weight: 700;
  line-height: 1;
}

.error-block h1 {
  font-size: 28px;
  margin-bottom: 12px;
}

.error-desc {
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}

.error-hints {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 460px;
  margin: 20px auto 0;
  text-align: left;
}

.error-hints li {
  position: relative;
  padding-left: 18px;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.7;
}

.error-hints li::before {
  content: "";
  position: absolute;
  top: 0.68em;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 1px;
  background-color: var(--accent);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 26px;
}

.error-links {
  max-width: 720px;
  margin: 34px auto 0;
}

.error-links h2 {
  font-size: 18px;
  margin-bottom: 14px;
  text-align: center;
}

.error-links ul {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.error-links a {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--panel);
  color: var(--text-2);
  font-size: 14px;
}

.error-links a:hover {
  color: var(--text);
  border-color: var(--text-3);
}

/* --------------------------------------------------------------------------
   5. responsive
   -------------------------------------------------------------------------- */

@media (max-width: 1080px) {
  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 420px);
    gap: 30px;
  }

  .hero h1 {
    font-size: 36px;
  }

  .page-layout,
  .page-content-notes .page-layout {
    grid-template-columns: minmax(0, 1fr) 280px;
    gap: 28px;
  }

  .status-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .channel-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .channel-item {
    border-left: none;
    border-top: 1px solid var(--line-soft);
  }

  .channel-item:nth-child(2n) {
    border-left: 1px solid var(--line-soft);
  }

  .channel-item:nth-child(-n + 2) {
    border-top: none;
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 58px;
  }

  .header-inner {
    padding: 0 16px;
    gap: 12px;
  }

  .brand-slogan {
    display: none;
  }

  /* 桌面导航收起，汉堡显示 */
  .site-nav.main-nav {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .mobile-nav {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 120;
    padding: 16px;
    background-color: #0a0c0e;
    overflow-y: auto;
  }

  .mobile-nav[hidden] {
    display: none;
  }

  .mobile-nav-close {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 44px;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    background-color: var(--panel);
    color: var(--text);
    font-size: 20px;
    line-height: 1;
    cursor: pointer;
  }

  .mobile-nav-close::before {
    content: "×";
  }

  .mobile-nav ul {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-top: 60px;
  }

  .mobile-nav a {
    display: flex;
    align-items: center;
    min-height: 48px;
    padding: 0 16px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background-color: var(--panel);
    color: var(--text-2);
    font-size: 16px;
  }

  .mobile-nav a.is-current {
    color: var(--text);
    font-weight: 700;
    border-color: var(--accent);
    box-shadow: inset 3px 0 0 var(--accent);
  }

  .site-main {
    padding: 0 16px 56px;
  }

  .inner-main {
    padding-top: 14px;
  }

  /* 首页：单列 */
  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    padding-bottom: 32px;
  }

  .hero h1 {
    font-size: 30px;
  }

  .hero-lead {
    font-size: 15px;
  }

  .hero-media img {
    height: 220px;
  }

  .choose-strip,
  .status-band,
  .checkerboard,
  .topic-preview,
  .notes-preview,
  .prep-preview,
  .faq-preview {
    padding: 32px 0;
  }

  .section-title {
    font-size: 21px;
  }

  .choose-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
    margin-top: 18px;
  }

  .status-list {
    display: flex;
    gap: 10px;
    overflow-x: auto;
    padding-bottom: 6px;
    scroll-snap-type: x proximity;
  }

  .status-item {
    flex: 0 0 220px;
    scroll-snap-align: start;
  }

  .checker-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
    margin-top: 22px;
    padding-top: 22px;
  }

  .checker-row.is-reversed .checker-media {
    order: 0;
  }

  .checker-media img {
    height: 200px;
  }

  .topic-item {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 14px;
    align-items: start;
  }

  .topic-cover img {
    height: 72px;
  }

  .topic-item > .card-link {
    grid-column: 1 / -1;
  }

  .notes-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .note-thumb img {
    height: 160px;
  }

  .prep-steps {
    grid-template-columns: minmax(0, 1fr);
  }

  .faq-preview-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .join-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    margin-top: 32px;
    padding: 20px;
  }

  /* 内页 */
  .page-title {
    font-size: 26px;
  }

  .page-header {
    padding-bottom: 16px;
    margin-bottom: 20px;
  }

  .page-hero {
    margin-bottom: 24px;
  }

  .page-hero-text,
  .page-hero-inner {
    padding: 18px;
  }

  .page-channel-map .page-hero,
  .page-viewing-prep .page-hero,
  .page-faq .page-hero {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-channel-map .page-hero-media,
  .page-viewing-prep .page-hero-figure,
  .page-faq .page-hero-media {
    border-left: none;
    border-top: 1px solid var(--line);
  }

  .page-hero-media img,
  .page-hero-figure img {
    max-height: 220px;
    min-height: 0;
    height: 220px;
  }

  /* 内页双栏 → 单列，主内容在前 */
  .page-layout,
  .page-content-notes .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }

  .page-aside,
  .notes-aside {
    position: static;
  }

  .notes-article {
    max-width: none;
  }

  .overview-points,
  .channel-list,
  .method-steps,
  .topic-intro-tips,
  .reading-order-steps,
  .scope-grid,
  .exclude-list,
  .basis-list,
  .boundary-section .boundary-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .channel-item {
    border-left: none;
    border-top: 1px solid var(--line-soft);
  }

  .channel-item:nth-child(2n) {
    border-left: none;
  }

  .channel-item:nth-child(-n + 2) {
    border-top: 1px solid var(--line-soft);
  }

  .channel-item:first-child {
    border-top: none;
  }

  .topic-entry {
    grid-template-columns: minmax(0, 1fr);
  }

  .topic-entry-media,
  .topic-entry-right .topic-entry-media {
    order: 0;
    border-left: none;
    border-right: none;
    border-bottom: 1px solid var(--line);
  }

  .topic-entry-right .topic-entry-body {
    order: 1;
  }

  .topic-entry-media img {
    height: 200px;
    min-height: 0;
  }

  .topic-entry-body {
    padding: 18px;
  }

  .prep-anchor-bar {
    position: static;
    margin-bottom: 22px;
  }

  .prep-anchor-bar ul {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .prep-anchor-bar a {
    white-space: nowrap;
  }

  .prep-item dd {
    grid-template-columns: minmax(0, 1fr);
  }

  .prep-overview-figure img,
  .fields-figure img,
  .notes-figure img {
    height: 200px;
  }

  .evidence-list li {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .faq-cat-nav ul {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .faq-cat-nav a {
    white-space: nowrap;
  }

  .field-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .field-list dt {
    border-bottom: none;
    padding-bottom: 2px;
    background-color: transparent;
  }

  .field-list dd {
    padding-top: 0;
    border-bottom: 1px solid var(--line);
  }

  .related-section .related-links li {
    flex: 1 1 100%;
  }

  /* 页脚两行 */
  .footer-inner {
    flex-wrap: wrap;
    gap: 12px;
    padding: 16px;
    min-height: 0;
  }

  .footer-brand {
    order: 1;
    flex: 1 1 auto;
  }

  .back-top {
    order: 2;
  }

  .footer-nav {
    order: 3;
    flex: 1 1 100%;
  }

  .footer-nav ul {
    justify-content: flex-start;
    gap: 4px 16px;
  }

  .footer-copy {
    padding: 0 16px 18px;
  }

  .error-main {
    padding-top: 40px;
    padding-bottom: 60px;
  }

  .error-block {
    padding: 26px 18px;
  }

  .error-code {
    font-size: 44px;
  }

  .error-block h1 {
    font-size: 22px;
  }

  .error-links ul {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 26px;
  }

  .page-title {
    font-size: 23px;
  }

  .btn {
    padding: 0 16px;
    font-size: 14px;
  }

  .hero-actions .btn {
    flex: 1 1 auto;
  }

  .topic-item {
    grid-template-columns: minmax(0, 1fr);
  }

  .topic-cover img {
    height: 120px;
  }

  .error-actions .btn {
    flex: 1 1 auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
}