/* =========================================================
   base — 基础变量、重置与全局骨架
   ========================================================= */
:root {
  --paper: #f5efe4;
  --paper-deep: #ece3d3;
  --ink: #1f2a3a;
  --ink-soft: #3a4a5e;
  --brick: #b85c38;
  --brick-dark: #9e4a2a;
  --line: #d8cdba;
  --tag-bg: #e8dfd0;
  --white: #fffdf8;
  --serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --sans: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --container: 1280px;
  --radius: 6px;
  --shadow: 0 1px 3px rgba(31, 42, 58, 0.08), 0 4px 14px rgba(31, 42, 58, 0.06);
  --shadow-lift: 0 4px 10px rgba(31, 42, 58, 0.1), 0 10px 28px rgba(31, 42, 58, 0.08);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
  background-color: var(--paper);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: var(--brick);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--brick-dark);
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1.35;
  color: var(--ink);
}

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.text-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--brick);
  border-bottom: 1px solid rgba(184, 92, 56, 0.4);
  padding-bottom: 2px;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.text-link:hover {
  color: var(--brick-dark);
  border-color: var(--brick-dark);
}

/* =========================================================
   layout — 页头、页脚、主容器与布局骨架
   ========================================================= */
.site-header {
  background-color: var(--paper);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 24px;
}

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

.brand-name {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.02em;
}

.brand-slogan {
  font-size: 12px;
  color: var(--ink-soft);
  letter-spacing: 0.05em;
  display: none;
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-list li {
  display: block;
}

.nav-link {
  display: block;
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-soft);
  border-radius: var(--radius);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  color: var(--brick);
  background-color: var(--tag-bg);
}

.nav-link.is-current {
  color: var(--brick);
  background-color: var(--tag-bg);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 44px;
  height: 44px;
  padding: 10px;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
}

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

.site-main {
  flex: 1 0 auto;
  width: 100%;
}

.site-footer {
  background-color: var(--paper-deep);
  border-top: 1px solid var(--line);
  padding: 28px 0;
  margin-top: 48px;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-brand {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.footer-nav {
  display: flex;
  gap: 24px;
}

.footer-link {
  font-size: 13px;
  color: var(--ink-soft);
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: var(--brick);
}

.footer-copy {
  font-size: 12px;
  color: var(--ink-soft);
  opacity: 0.8;
}

/* 内页骨架 */
.site-inner {
  background-color: var(--paper);
}

.inner-main {
  padding-top: 32px;
  padding-bottom: 40px;
}

.breadcrumb {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px 20px;
  font-size: 13px;
  color: var(--ink-soft);
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb a {
  color: var(--ink-soft);
}

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

.breadcrumb-sep {
  color: var(--line);
  font-size: 12px;
}

.breadcrumb-current {
  color: var(--ink);
  font-weight: 600;
}

.page-header {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px 28px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 32px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.page-description {
  font-size: 15px;
  color: var(--ink-soft);
  max-width: 720px;
  line-height: 1.7;
}

.page-lead {
  font-size: 14px;
  color: var(--ink-soft);
  margin-top: 12px;
  padding-left: 16px;
  border-left: 3px solid var(--brick);
}

/* 三栏文档式布局 */
.layout-shell {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  gap: 32px;
}

.layout-shell.sidebar-left {
  grid-template-columns: 220px minmax(0, 1fr) 200px;
  align-items: start;
}

/* 专题页两栏 */
.layout-shell-topics {
  grid-template-columns: 180px minmax(0, 1fr);
  align-items: start;
}

/* 侧栏公共 */
.side-panel {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 24px;
}

.side-title {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.side-index-list,
.side-toc-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.side-index-list a,
.side-toc-list a {
  display: block;
  padding: 6px 8px;
  font-size: 13px;
  color: var(--ink-soft);
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.side-index-list a:hover,
.side-toc-list a:hover {
  background-color: var(--tag-bg);
  color: var(--brick);
}

.side-index-list .is-current,
.side-toc-list .is-current {
  color: var(--brick);
  font-weight: 600;
  background-color: var(--tag-bg);
}

/* =========================================================
   components — 通用组件
   ========================================================= */
.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 10px;
  position: relative;
  padding-left: 16px;
}

.section-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 4px;
  background-color: var(--brick);
  border-radius: 2px;
}

.section-desc {
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 24px;
  max-width: 720px;
}

/* 面包屑 */
.breadcrumb {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px 20px;
  font-size: 13px;
  color: var(--ink-soft);
}

.breadcrumb a {
  color: var(--ink-soft);
}

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

.breadcrumb-sep {
  margin: 0 8px;
  color: var(--line);
}

.breadcrumb-current {
  color: var(--ink);
  font-weight: 600;
}

/* 图片容器 */
figure {
  margin: 0;
}

figcaption {
  font-size: 12px;
  color: var(--ink-soft);
  padding-top: 8px;
  text-align: center;
  line-height: 1.5;
}

/* =========================================================
   pages — 首页
   ========================================================= */
.home-main {
  padding-bottom: 20px;
}

/* hero 资源工具区 */
.hero-resource {
  background-color: var(--paper-deep);
  border-bottom: 1px solid var(--line);
  padding: 40px 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 1.4fr 1fr;
  gap: 28px;
  align-items: stretch;
}

.hero-filter {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
}

.hero-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  margin-bottom: 4px;
}

.hero-intro {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 320px;
}

.purpose-filter {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 8px;
}

.filter-btn {
  display: inline-block;
  padding: 10px 18px;
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  text-align: center;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
  box-shadow: var(--shadow);
}

.filter-btn:hover {
  background-color: var(--brick);
  border-color: var(--brick);
  color: var(--white);
}

.hero-media {
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  box-shadow: var(--shadow);
}

.hero-media img {
  width: 100%;
  height: 240px;
  object-fit: cover;
  border-radius: 4px;
}

.hero-media figcaption {
  padding-top: 10px;
  font-size: 13px;
}

.hero-updates {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: var(--shadow);
}

.updates-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.update-item {
  background-color: var(--paper);
  border-radius: 4px;
  padding: 12px;
}

.version-tag {
  display: inline-block;
  background-color: var(--tag-bg);
  color: var(--ink);
  font-size: 12px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 3px;
  margin-bottom: 6px;
}

.update-summary {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* 频道分类总览 */
.channel-overview {
  padding: 48px 0 24px;
}

.channel-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.channel-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow);
}

.channel-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.channel-sn {
  display: inline-block;
  font-family: var(--serif);
  font-size: 13px;
  color: var(--brick);
  background-color: var(--tag-bg);
  padding: 2px 8px;
  border-radius: 3px;
  margin-bottom: 10px;
  font-weight: 700;
}

.channel-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.channel-desc {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
  margin-bottom: 12px;
}

.channel-tag {
  display: inline-block;
  font-size: 12px;
  color: var(--ink-soft);
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 2px 8px;
}

/* 专题片单精选 */
.topic-showcase {
  padding: 48px 0 24px;
}

.topic-scroll {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.topic-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow);
}

.topic-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.topic-card img {
  width: 100%;
  height: 140px;
  object-fit: cover;
  display: block;
}

.topic-card .topic-sn {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: var(--brick);
  background-color: var(--tag-bg);
  padding: 2px 8px;
  border-radius: 3px;
  margin: 12px 12px 0;
}

.topic-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  padding: 8px 12px 0;
  margin-bottom: 4px;
}

.topic-tag {
  display: inline-block;
  font-size: 12px;
  color: var(--ink-soft);
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 2px 8px;
  margin: 0 0 12px 12px;
}

/* 观看指南速览 */
.guide-snapshot {
  padding: 48px 0 24px;
}

.steps-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 24px;
}

.step-item {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: relative;
  box-shadow: var(--shadow);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background-color: var(--brick);
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 10px;
}

.step-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 6px;
}

.step-text {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.check-tip {
  background-color: var(--tag-bg);
  border-left: 4px solid var(--brick);
  border-radius: 4px;
  padding: 16px 20px;
  font-size: 14px;
  color: var(--ink-soft);
}

.check-tip strong {
  color: var(--ink);
  margin-right: 6px;
}

.check-tip a {
  margin-left: 8px;
  font-weight: 600;
}

/* 最新动态条目 */
.updates-list {
  padding: 48px 0 24px;
}

.update-entries {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.update-entry {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  box-shadow: var(--shadow);
}

.version-badge {
  display: inline-block;
  background-color: var(--brick);
  color: var(--white);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 4px;
  white-space: nowrap;
  flex-shrink: 0;
}

.update-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* 问题与反馈入口 */
.feedback-entry {
  padding: 48px 0 24px;
}

.feedback-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.feedback-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow);
}

.feedback-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.feedback-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.feedback-text {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
  margin-bottom: 12px;
}

/* 相关链接 */
.related-links {
  padding: 8px 0 32px;
}

.related-links-label {
  font-size: 13px;
  color: var(--ink-soft);
  margin-right: 12px;
}

.related-links-item {
  font-size: 13px;
  margin-right: 16px;
  border-bottom: 1px solid rgba(184, 92, 56, 0.3);
}

/* =========================================================
   pages — 频道分类页
   ========================================================= */
.channel-detail-block {
  margin-bottom: 32px;
}

.channel-detail-block .channel-card {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 24px;
  padding: 0;
  overflow: hidden;
}

.channel-card-media {
  background-color: var(--paper-deep);
}

.channel-card-media img {
  width: 100%;
  height: 100%;
  min-height: 160px;
  object-fit: cover;
}

.channel-card-body {
  padding: 24px 24px 24px 0;
}

.channel-card-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.channel-number {
  font-family: var(--serif);
  font-size: 13px;
  font-weight: 700;
  color: var(--brick);
  background-color: var(--tag-bg);
  padding: 2px 8px;
  border-radius: 3px;
}

.channel-card-head .channel-name {
  font-size: 18px;
  margin-bottom: 0;
}

.channel-intro {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 14px;
}

.topic-tags li {
  display: inline-block;
  font-size: 12px;
  color: var(--ink-soft);
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 2px 8px;
}

.channel-related {
  font-size: 13px;
  font-weight: 600;
}

.channel-note-block {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 40px;
}

.block-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 12px;
}

.block-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 8px;
}

.block-desc a {
  font-weight: 600;
}

/* =========================================================
   pages — 专题片单页
   ========================================================= */
.topic-timeline {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: 88px;
}

.aside-title {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.timeline-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.timeline-item a {
  display: block;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--ink-soft);
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.timeline-item a:hover {
  background-color: var(--tag-bg);
  color: var(--brick);
}

.timeline-note {
  font-size: 12px;
  color: var(--ink-soft);
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  line-height: 1.6;
}

.topic-cards {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.topic-cards .topic-card {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 0;
  overflow: hidden;
}

.topic-card-media {
  background-color: var(--paper-deep);
}

.topic-cover {
  width: 100%;
  height: 100%;
  min-height: 180px;
  object-fit: cover;
}

.topic-card-body {
  padding: 24px;
}

.topic-number {
  font-family: var(--serif);
  font-size: 13px;
  font-weight: 700;
  color: var(--brick);
  background-color: var(--tag-bg);
  display: inline-block;
  padding: 2px 10px;
  border-radius: 3px;
  margin-bottom: 10px;
}

.topic-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.topic-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
}

.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 14px;
}

.topic-tags .topic-tag {
  margin: 0;
}

.topic-composition {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.topic-composition a {
  font-weight: 600;
  margin-right: 12px;
}

.topic-usage,
.topic-channel-note {
  padding: 40px 0 0;
}

.topic-usage p,
.topic-channel-note p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
  max-width: 780px;
}

/* =========================================================
   pages — 观看指南页
   ========================================================= */
.guide-sidebar {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: 88px;
}

.sidebar-title {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.sidebar-nav-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sidebar-nav-list a {
  display: block;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--ink-soft);
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.sidebar-nav-list a:hover {
  background-color: var(--tag-bg);
  color: var(--brick);
}

.sidebar-note {
  font-size: 12px;
  color: var(--ink-soft);
  margin-top: 14px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  line-height: 1.6;
}

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

.guide-figure {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  margin-bottom: 32px;
  box-shadow: var(--shadow);
}

.guide-figure img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: 4px;
}

.guide-step {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
}

.step-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--brick);
  color: var(--white);
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

.step-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.step-text {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
}

.step-link {
  font-size: 14px;
  font-weight: 600;
  display: inline-block;
  margin-top: 4px;
}

.guide-checkaside {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: 88px;
}

.check-intro {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
  margin-bottom: 14px;
}

.check-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 14px;
}

.check-item {
  background-color: var(--paper);
  border-radius: 4px;
  padding: 10px 12px;
  border-left: 3px solid var(--brick);
}

.check-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 2px;
}

.check-desc {
  font-size: 12px;
  color: var(--ink-soft);
  line-height: 1.5;
}

.check-footer {
  font-size: 13px;
  color: var(--ink-soft);
  padding-top: 12px;
  border-top: 1px solid var(--line);
  line-height: 1.6;
}

.check-footer a {
  font-weight: 600;
  margin-right: 10px;
}

/* =========================================================
   pages — 更新记录页
   ========================================================= */
.latest-badge {
  margin-bottom: 40px;
}

.latest-badge-inner {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 32px;
  align-items: center;
  box-shadow: var(--shadow);
}

.latest-flag {
  display: inline-block;
  background-color: var(--brick);
  color: var(--white);
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 3px;
  margin-bottom: 10px;
  letter-spacing: 0.04em;
}

.latest-version {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.latest-summary {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
}

.content-media {
  background-color: var(--paper-deep);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px;
}

.content-media img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 4px;
}

.content-media-inline {
  margin: 20px 0;
}

.version-list {
  padding: 0 0 40px;
}

.version-group {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 28px;
  margin-bottom: 20px;
  box-shadow: var(--shadow);
}

.version-group-header {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.version-number {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 700;
  color: var(--brick);
}

.version-date {
  font-size: 13px;
  color: var(--ink-soft);
}

.version-changes {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.version-changes li {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
  padding-left: 20px;
  position: relative;
}

.version-changes li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  width: 6px;
  height: 6px;
  background-color: var(--brick);
  border-radius: 50%;
}

.related-links-inner {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  padding: 20px 0 40px;
}

.related-link {
  font-size: 14px;
  font-weight: 600;
  padding: 8px 16px;
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.related-link:hover {
  border-color: var(--brick);
  color: var(--brick);
}

/* =========================================================
   pages — 内容边界页
   ========================================================= */
.policy-intro {
  margin-bottom: 48px;
}

.intro-media {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  margin-bottom: 20px;
}

.policy-figure {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 10px;
  box-shadow: var(--shadow);
}

.policy-figure img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 4px;
}

.intro-text {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 12px;
}

.policy-table-section {
  margin-bottom: 48px;
}

.policy-table-wrap {
  overflow-x: auto;
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.policy-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 560px;
}

.policy-table th,
.policy-table td {
  padding: 14px 20px;
  text-align: left;
  font-size: 14px;
  border-bottom: 1px solid var(--line);
}

.policy-table th {
  background-color: var(--tag-bg);
  font-family: var(--serif);
  font-weight: 700;
  color: var(--ink);
}

.policy-table tr:last-child td {
  border-bottom: none;
}

.policy-table td {
  color: var(--ink-soft);
  line-height: 1.6;
}

.policy-table td:first-child {
  font-weight: 600;
  color: var(--ink);
}

.policy-rules {
  margin-bottom: 48px;
}

.rules-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.rule-item {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 24px;
  box-shadow: var(--shadow);
}

.rule-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 6px;
}

.rule-text {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.policy-related {
  padding-bottom: 20px;
}

.policy-related .related-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  padding: 0;
}

/* =========================================================
   pages — 问题反馈页
   ========================================================= */
.aside-nav {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: 88px;
}

.aside-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.aside-link {
  display: block;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--ink-soft);
  border-radius: 4px;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.aside-link:hover {
  background-color: var(--tag-bg);
  color: var(--brick);
}

.faq-section {
  margin-bottom: 48px;
}

.faq-item {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.faq-question {
  display: block;
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  position: relative;
  padding-right: 44px;
  transition: background-color 0.2s ease;
}

.faq-question:hover {
  background-color: var(--paper);
}

.faq-question::after {
  content: "+";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--brick);
  font-weight: 400;
  transition: transform 0.2s ease;
}

details[open] .faq-question::after {
  content: "−";
  transform: translateY(-50%);
}

.faq-answer {
  padding: 0 20px 16px;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.path-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}

.path-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

.path-body {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* =========================================================
   pages — 404
   ========================================================= */
.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
}

.error-inner {
  max-width: 640px;
  width: 100%;
}

.error-panel {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 48px 40px;
  text-align: center;
  box-shadow: var(--shadow);
}

.error-code {
  font-family: var(--serif);
  font-size: 64px;
  font-weight: 700;
  color: var(--brick);
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 22px;
  color: var(--ink);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 24px;
}

.error-back {
  display: inline-block;
  padding: 10px 24px;
  background-color: var(--brick);
  color: var(--white);
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  transition: background-color 0.2s ease;
}

.error-back:hover {
  background-color: var(--brick-dark);
  color: var(--white);
}

/* =========================================================
   responsive — 响应式断点
   ========================================================= */
@media (min-width: 1025px) {
  .brand-slogan {
    display: inline-block;
  }
}

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr 1fr;
  }

  .hero-updates {
    grid-column: 1 / -1;
  }

  .layout-shell.sidebar-left {
    grid-template-columns: 200px minmax(0, 1fr);
  }

  .sidebar-right-toc {
    display: none;
  }

  .topic-scroll {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 860px) {
  .header-inner {
    height: 60px;
  }

  .brand-slogan {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background-color: var(--paper);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 8px 16px rgba(31, 42, 58, 0.08);
    display: block;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    padding: 12px 24px 20px;
    gap: 4px;
    max-height: calc(100vh - 60px);
    overflow-y: auto;
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-link {
    padding: 10px 12px;
    font-size: 15px;
  }

  .layout-shell.sidebar-left {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .sidebar-left-nav,
  .guide-sidebar,
  .aside-nav {
    position: static;
    order: 2;
    margin-top: 24px;
  }

  .central-content {
    order: 1;
  }

  .sidebar-right-toc {
    display: none;
  }

  .layout-shell-topics {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .topic-timeline {
    position: static;
    order: 2;
  }

  .topic-cards {
    order: 1;
  }

  .latest-badge-inner {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .intro-media {
    grid-template-columns: 1fr;
  }

  .path-grid {
    grid-template-columns: 1fr;
  }

  .channel-detail-block .channel-card {
    grid-template-columns: 1fr;
  }

  .channel-card-media img {
    height: 160px;
  }

  .channel-card-body {
    padding: 20px;
  }

  .topic-cards .topic-card {
    grid-template-columns: 1fr;
  }

  .topic-cover {
    height: 180px;
  }

  .steps-row {
    grid-template-columns: 1fr;
  }

  .update-entries {
    grid-template-columns: 1fr;
  }

  .feedback-cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .hero-title {
    font-size: 24px;
  }

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

  .topic-scroll {
    grid-template-columns: 1fr;
  }

  .channel-grid {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .footer-nav {
    flex-wrap: wrap;
    gap: 12px 20px;
  }

  .page-title {
    font-size: 24px;
  }

  .page-header {
    padding-bottom: 20px;
    margin-bottom: 24px;
  }

  .latest-badge-inner {
    padding: 20px;
  }

  .content-media img {
    height: 140px;
  }

  .version-group {
    padding: 18px;
  }

  .version-group-header {
    flex-direction: column;
    gap: 4px;
  }

  .guide-figure img {
    height: 160px;
  }

  .guide-step {
    padding: 20px;
  }

  .policy-table-wrap {
    margin-left: -16px;
    margin-right: -16px;
    border-radius: 0;
    border-left: none;
    border-right: none;
  }

  .policy-table {
    min-width: 520px;
  }

  .error-panel {
    padding: 32px 20px;
  }

  .error-code {
    font-size: 48px;
  }
}

@media (max-width: 390px) {
  html {
    font-size: 15px;
  }

  .brand-name {
    font-size: 20px;
  }

  .filter-btn {
    padding: 12px 16px;
    font-size: 14px;
  }

  .hero-updates {
    padding: 16px;
  }

  .channel-card,
  .step-item,
  .update-entry,
  .feedback-card {
    padding: 16px;
  }

  .topic-card-body {
    padding: 16px;
  }

  .faq-question {
    padding: 14px 40px 14px 16px;
    font-size: 14px;
  }

  .faq-answer {
    padding: 0 16px 14px;
    font-size: 13px;
  }
}