/* ============================================================
   宅男影院 · 全站样式表
   视觉方向：深色墨灰底、亮白文字、橙色强调、蓝色辅助
   ============================================================ */

/* ============================================================
   01 · Base — 重置、变量、全局基础
   ============================================================ */

:root {
  --color-bg: #16181D;
  --color-surface: #1F232B;
  --color-surface-light: #242932;
  --color-border: #2A2F38;
  --color-text: #E8EAED;
  --color-text-secondary: #A0A6B1;
  --color-accent: #E8873A;
  --color-accent-light: #F09A55;
  --color-blue: #3A7CA5;
  --color-blue-light: #4E8FB8;

  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
  --font-num: "DIN Alternate", "Bahnschrift", "Arial Narrow", var(--font-sans);

  --container-width: 1200px;
  --container-padding: 24px;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;

  --header-height: 64px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-text);
}

figure {
  margin: 0;
}

details {
  display: block;
}

summary {
  cursor: pointer;
  list-style: none;
}

summary::-webkit-details-marker {
  display: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================================
   02 · Layout — 全局布局骨架
   ============================================================ */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-bg);
}

.site-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.brand-link {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.brand-tagline {
  font-size: 12px;
  color: var(--color-text-secondary);
  margin-top: 2px;
}

.site-nav {
  margin-left: auto;
}

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

.nav-list li a {
  display: block;
  padding: 10px 16px;
  font-size: 15px;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-list li a:hover {
  color: var(--color-text);
  background-color: var(--color-surface-light);
}

.nav-list li a.is-current {
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
}

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

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

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

.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 32px var(--container-padding) 56px;
}

.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 32px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 32px;
}

.footer-brand-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.footer-brand-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.footer-col-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 12px;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links li a {
  font-size: 14px;
  color: var(--color-text-secondary);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding: 20px var(--container-padding);
  text-align: center;
}

.copyright {
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* ============================================================
   03 · Components — 通用组件
   ============================================================ */

/* --- 面包屑 --- */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

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

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

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

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

/* --- 页面标题区 --- */

.page-header {
  margin-bottom: 32px;
}

.page-title {
  font-size: 30px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.page-description {
  font-size: 16px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 720px;
}

/* --- 区块标题 --- */

.section-heading {
  margin-bottom: 24px;
}

.section-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.section-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.section-intro {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

/* --- 页面布局：主内容 + 侧栏 --- */

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 32px;
  align-items: start;
}

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

/* --- 卡片通用 --- */

.channel-card,
.topic-card,
.path-card,
.era-card,
.era-archive-group,
.theme-item,
.group-card,
.step-card,
.process-step,
.tip-card,
.aside-card,
.sidebar-item,
.info-tip {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--transition-base), border-color var(--transition-base);
}

.channel-card:hover,
.topic-card:hover,
.path-card:hover,
.era-card:hover,
.era-archive-group:hover,
.theme-item:hover,
.group-card:hover,
.step-card:hover,
.process-step:hover,
.tip-card:hover,
.aside-card:hover,
.sidebar-item:hover,
.info-tip:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
}

/* --- FAQ 折叠 --- */

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

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  cursor: pointer;
  position: relative;
  padding-right: 44px;
}

.faq-question::after {
  content: "+";
  position: absolute;
  right: 18px;
  font-size: 20px;
  color: var(--color-accent);
  transition: transform var(--transition-fast);
}

.faq-item[open] .faq-question::after {
  transform: rotate(45deg);
}

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

/* --- 相关链接 --- */

.related-links {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding) 0;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.related-links-label {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.related-links-item {
  font-size: 14px;
  color: var(--color-accent);
}

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

/* --- 反馈横幅 --- */

.feedback-banner {
  max-width: var(--container-width);
  margin: 48px auto 0;
  padding: 0 var(--container-padding);
}

.feedback-inner,
.feedback-banner-content {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.feedback-title,
.feedback-banner-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.feedback-text,
.feedback-banner-text {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.feedback-link,
.feedback-banner-link {
  flex-shrink: 0;
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: #fff;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.feedback-link:hover,
.feedback-banner-link:hover {
  background-color: var(--color-accent-light);
  color: #fff;
}

/* --- 按钮 --- */

.btn-primary {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: #fff;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

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

.btn-secondary {
  display: inline-block;
  padding: 12px 28px;
  background-color: transparent;
  color: var(--color-text);
  font-size: 15px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* --- 文本链接 --- */

.text-link {
  font-size: 14px;
  color: var(--color-accent);
}

.text-link:hover {
  color: var(--color-accent-light);
}

/* ============================================================
   04 · Pages — 首页
   ============================================================ */

.home-main {
  padding-bottom: 48px;
}

/* --- 首屏：频道地图 + 频道列表 --- */

.hero-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--container-padding) 24px;
}

.hero-layout {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 32px;
  align-items: stretch;
}

.hero-map {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
}

.hero-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.hero-lead {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.hero-figure {
  margin-bottom: 20px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
}

.hero-figure img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.hero-figure figcaption {
  padding: 10px 14px;
  font-size: 13px;
  color: var(--color-text-secondary);
  background-color: var(--color-surface-light);
}

.map-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: auto;
}

.map-tag {
  display: inline-block;
  padding: 8px 16px;
  font-size: 14px;
  color: var(--color-blue);
  background-color: rgba(58, 124, 165, 0.12);
  border: 1px solid rgba(58, 124, 165, 0.3);
  border-radius: 999px;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.map-tag:hover {
  background-color: rgba(58, 124, 165, 0.22);
  color: var(--color-blue-light);
}

.hero-channels {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.hero-channels .section-heading {
  margin-bottom: 16px;
}

.hero-channels .section-title {
  font-size: 20px;
}

.channel-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.channel-item {
  border-bottom: 1px solid var(--color-border);
}

.channel-item:last-child {
  border-bottom: none;
}

.channel-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 8px;
  color: var(--color-text);
  transition: background-color var(--transition-fast);
  border-radius: var(--radius-sm);
}

.channel-link:hover {
  background-color: var(--color-surface-light);
  color: var(--color-text);
}

.channel-tag {
  flex-shrink: 0;
  display: inline-block;
  padding: 4px 12px;
  font-size: 13px;
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
  border-radius: var(--radius-sm);
}

.channel-desc {
  flex: 1;
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.channel-more {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
  padding: 8px 0;
}

.channel-more:hover {
  color: var(--color-accent-light);
}

/* --- 入门到进阶路径 --- */

.path-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 0;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.path-card {
  padding: 24px;
  position: relative;
}

.path-card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 10px;
}

.path-card-text {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.path-card-text a {
  color: var(--color-blue);
}

.path-card-text a:hover {
  color: var(--color-blue-light);
}

.path-link {
  font-size: 14px;
  color: var(--color-accent);
}

.path-link:hover {
  color: var(--color-accent-light);
}

/* --- 时期索引摘要 --- */

.era-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 0;
}

.era-timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 20px;
  position: relative;
}

.era-timeline::before {
  content: "";
  position: absolute;
  top: 16px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-border);
}

.era-node {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  position: relative;
}

.era-node::before {
  content: "";
  position: absolute;
  top: 8px;
  left: 20px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 3px solid var(--color-bg);
  z-index: 1;
}

.era-period {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
  padding-top: 16px;
}

.era-range {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
  font-family: var(--font-num);
}

.era-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.era-tag {
  display: inline-block;
  padding: 3px 10px;
  font-size: 12px;
  color: var(--color-blue);
  background-color: rgba(58, 124, 165, 0.1);
  border-radius: 999px;
}

.era-more {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
  padding: 8px 0;
}

.era-more:hover {
  color: var(--color-accent-light);
}

/* --- 专题研究横排 --- */

.topic-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 0;
}

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

.topic-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.topic-figure {
  overflow: hidden;
  background-color: var(--color-surface-light);
}

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

.topic-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  padding: 16px 20px 4px;
}

.topic-angle {
  font-size: 13px;
  color: var(--color-accent);
  padding: 0 20px 8px;
}

.topic-bg {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  padding: 0 20px 16px;
  flex: 1;
}

.topic-link {
  display: block;
  font-size: 14px;
  color: var(--color-accent);
  padding: 0 20px 20px;
}

.topic-link:hover {
  color: var(--color-accent-light);
}

.topic-more {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
  padding: 8px 0;
}

.topic-more:hover {
  color: var(--color-accent-light);
}

/* --- 观看指南步骤摘要 --- */

.guide-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 0;
}

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

.guide-step {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.guide-step-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 10px;
  position: relative;
  padding-left: 36px;
}

.guide-step-title::before {
  content: attr(data-step);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-family: var(--font-num);
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
  border-radius: 50%;
}

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

.guide-step-text a {
  color: var(--color-blue);
}

.guide-step-text a:hover {
  color: var(--color-blue-light);
}

.guide-link {
  font-size: 14px;
  color: var(--color-accent);
}

.guide-link:hover {
  color: var(--color-accent-light);
}

/* ============================================================
   05 · Pages — 频道地图
   ============================================================ */

.channel-list-section,
.map-overview-section {
  margin-bottom: 40px;
}

.channel-card-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.channel-card {
  display: flex;
  gap: 16px;
  padding: 16px;
  overflow: hidden;
}

.channel-card-media {
  flex-shrink: 0;
  width: 140px;
  height: 100px;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
}

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

.channel-card-body {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.channel-card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
}

.channel-type {
  font-size: 13px;
  color: var(--color-accent);
}

.channel-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.channel-audience {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.channel-audience strong {
  color: var(--color-blue);
  font-weight: 500;
}

.channel-entry {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
  margin-top: auto;
}

.channel-entry:hover {
  color: var(--color-accent-light);
}

.map-overview-block {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 24px;
  align-items: stretch;
}

.map-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
}

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

.map-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--color-text-secondary);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

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

.map-direction-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  flex: 1;
}

.direction-tag {
  display: inline-block;
  font-size: 13px;
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
}

.direction-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- 侧栏 --- */

.side-bar,
.guide-aside,
.layout-aside {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.side-bar h2,
.guide-aside h2,
.layout-aside h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 16px;
}

.tip-card,
.aside-card {
  border: none;
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 16px 0;
}

.tip-card:last-child,
.aside-card:last-child {
  border-bottom: none;
}

.tip-title,
.aside-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.tip-desc,
.aside-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.tip-desc a,
.aside-desc a {
  color: var(--color-blue);
}

.tip-desc a:hover,
.aside-desc a:hover {
  color: var(--color-blue-light);
}

/* ============================================================
   06 · Pages — 时期索引
   ============================================================ */

.era-timeline-section,
.era-archive-section,
.era-theme-section {
  margin-bottom: 40px;
}

.era-timeline-list {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-left: 32px;
}

.era-timeline-list::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--color-border);
}

.era-timeline-item {
  position: relative;
}

.era-timeline-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 24px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 3px solid var(--color-bg);
  z-index: 1;
}

.era-card {
  padding: 20px 24px;
}

.era-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.era-range {
  font-size: 13px;
  color: var(--color-text-secondary);
  font-family: var(--font-num);
  margin-bottom: 8px;
}

.era-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 12px;
}

.era-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.era-tags li {
  display: inline-block;
  padding: 4px 12px;
  font-size: 13px;
  color: var(--color-blue);
  background-color: rgba(58, 124, 165, 0.1);
  border-radius: 999px;
}

.era-archive-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.era-archive-group {
  padding: 20px;
}

.archive-group-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.archive-year-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.archive-year-list li a {
  display: block;
  font-size: 14px;
  color: var(--color-text-secondary);
  padding: 6px 0;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.archive-year-list li a:hover {
  color: var(--color-accent);
  padding-left: 6px;
}

/* --- 时期索引内页布局 --- */

.page-layout .layout-main {
  min-width: 0;
}

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

.theme-item {
  overflow: hidden;
}

.theme-image {
  width: 100%;
  height: 140px;
  object-fit: cover;
}

.theme-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  padding: 14px 16px 4px;
}

.theme-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  padding: 0 16px 16px;
}

.layout-aside {
  align-self: start;
}

.aside-card {
  padding: 14px 0;
}

.aside-card h2 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.aside-card .aside-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.aside-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
}

.aside-link {
  font-size: 14px;
  color: var(--color-accent);
}

.aside-link:hover {
  color: var(--color-accent-light);
}

/* ============================================================
   07 · Pages — 专题研究
   ============================================================ */

.topic-grid-section {
  margin-bottom: 40px;
}

.topic-grid-section .topic-grid {
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.topic-grid-section .topic-card {
  display: flex;
  flex-direction: row;
  gap: 0;
}

.topic-figure {
  flex-shrink: 0;
  width: 180px;
  min-height: 100%;
}

.topic-figure img {
  width: 100%;
  height: 100%;
  min-height: 200px;
  object-fit: cover;
}

.topic-body {
  flex: 1;
  min-width: 0;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.topic-label {
  display: inline-block;
  align-self: flex-start;
  font-size: 12px;
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
}

.topic-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

.topic-angle {
  font-size: 13px;
  color: var(--color-blue);
}

.topic-bg {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  flex: 1;
}

.topic-meta {
  font-size: 13px;
  color: var(--color-text-secondary);
  border-top: 1px solid var(--color-border);
  padding-top: 10px;
  margin-top: auto;
}

.topic-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.topic-list li {
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* --- 侧栏 --- */

.sidebar {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  align-self: start;
}

.sidebar-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 16px;
}

.sidebar-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 20px;
}

.sidebar-item {
  border: none;
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 0 0 16px;
}

.sidebar-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.sidebar-item-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.sidebar-item-text {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.sidebar-link {
  display: inline-block;
  font-size: 14px;
  color: var(--color-accent);
}

.sidebar-link:hover {
  color: var(--color-accent-light);
}

/* ============================================================
   08 · Pages — 观看指南
   ============================================================ */

.guide-section {
  margin-bottom: 40px;
}

.guide-section .section-title {
  font-size: 22px;
}

.content-media {
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
  margin-bottom: 20px;
}

.content-media img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.content-media figcaption {
  padding: 10px 14px;
  font-size: 13px;
  color: var(--color-text-secondary);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

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

.step-card {
  padding: 24px;
  position: relative;
}

.step-card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 10px;
  position: relative;
  padding-left: 36px;
}

.step-card-title::before {
  content: attr(data-step);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-family: var(--font-num);
  color: var(--color-accent);
  background-color: rgba(232, 135, 58, 0.1);
  border-radius: 50%;
}

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

.step-card-link {
  font-size: 14px;
  color: var(--color-accent);
}

.step-card-link:hover {
  color: var(--color-accent-light);
}

/* --- 进阶方法 --- */

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

.feature-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.feature-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 10px;
}

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

.feature-link {
  font-size: 14px;
  color: var(--color-accent);
}

.feature-link:hover {
  color: var(--color-accent-light);
}

/* --- 入口核验步骤 --- */

.verify-steps {
  display: flex;
  flex-direction: column;
  gap: 12px;
  counter-reset: verify-counter;
}

.verify-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  counter-increment: verify-counter;
}

.verify-step::before {
  content: counter(verify-counter, decimal-leading-zero);
  flex-shrink: 0;
  font-family: var(--font-num);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.4;
}

.verify-step-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.verify-step-text {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- 侧栏 --- */

.guide-aside {
  align-self: start;
}

.guide-aside .aside-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 16px;
}

.guide-aside .faq-list {
  margin-bottom: 16px;
}

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

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

.guide-aside .aside-link {
  font-size: 14px;
  color: var(--color-accent);
}

.guide-aside .aside-link:hover {
  color: var(--color-accent-light);
}

/* --- 观看指南页反馈横幅 --- */

.guide-section + .feedback-banner {
  margin-top: 0;
}

/* ============================================================
   09 · Pages — 问题反馈
   ============================================================ */

.layout-shell {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.faq-section,
.feedback-process {
  margin-bottom: 40px;
}

.faq-section .faq-question {
  font-size: 15px;
}

.faq-section .faq-answer {
  font-size: 14px;
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.process-step {
  padding: 20px;
  position: relative;
}

.step-num {
  display: inline-block;
  font-family: var(--font-num);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.step-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.process-step p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.process-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
}

.process-figure img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.process-figure figcaption {
  padding: 10px 14px;
  font-size: 13px;
  color: var(--color-text-secondary);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

/* --- 侧栏 --- */

.sidebar .sidebar-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.info-tips-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 20px;
}

.info-tip {
  border: none;
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
  padding: 0 0 14px;
}

.info-tip:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.info-tip .tip-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.info-tip p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.sidebar-link-box {
  background-color: var(--color-surface-light);
  border-radius: var(--radius-md);
  padding: 16px;
}

.sidebar-link-box p {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
}

.sidebar-link-box .text-link {
  font-size: 14px;
}

/* --- 反馈入口条 --- */

.feedback-entry-bar {
  max-width: var(--container-width);
  margin: 0 auto 48px;
  padding: 0 var(--container-padding);
}

.entry-bar-inner {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.entry-text h2 {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.entry-text p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.entry-link {
  flex-shrink: 0;
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: #fff;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.entry-link:hover {
  background-color: var(--color-accent-light);
  color: #fff;
}

/* ============================================================
   10 · Pages — 站点地图
   ============================================================ */

.page-container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding) 48px;
}

.sitemap-overview {
  margin-bottom: 40px;
}

.sitemap-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-surface-light);
  margin-bottom: 16px;
}

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

.sitemap-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.sitemap-groups {
  margin-bottom: 40px;
}

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

.group-card {
  padding: 24px;
}

.group-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}

.group-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.group-link {
  font-size: 14px;
  color: var(--color-accent);
}

.group-link:hover {
  color: var(--color-accent-light);
}

.sitemap-pages {
  margin-bottom: 40px;
}

.page-entry-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-entry-item {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 12px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.entry-link {
  flex-shrink: 0;
  min-width: 140px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-accent);
}

.entry-link:hover {
  color: var(--color-accent-light);
}

.entry-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ============================================================
   11 · Pages — 404
   ============================================================ */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px var(--container-padding);
}

.error-panel {
  max-width: 560px;
  text-align: center;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 48px 40px;
}

.error-code {
  font-family: var(--font-num);
  font-size: 72px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 20px;
}

.error-help {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.error-help a {
  color: var(--color-accent);
}

.error-help a:hover {
  color: var(--color-accent-light);
}

/* ============================================================
   12 · Responsive — 响应式
   ============================================================ */

@media (max-width: 1024px) {
  .footer-inner {
    grid-template-columns: 2fr 1fr 1fr;
    gap: 24px;
  }

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

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

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

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

  .topic-grid-section .topic-figure {
    width: 160px;
  }

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

  .hero-layout {
    grid-template-columns: 1fr;
  }

  .hero-figure img {
    height: 240px;
  }

  .map-overview-block {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --container-padding: 16px;
  }

  .header-inner {
    height: auto;
    min-height: var(--header-height);
    flex-wrap: wrap;
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    flex-basis: 100%;
    margin-left: 0;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    width: 100%;
    padding: 8px 0 16px;
    gap: 0;
  }

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

  .nav-list li {
    width: 100%;
  }

  .nav-list li a {
    padding: 14px 16px;
    border-radius: var(--radius-sm);
  }

  .page-layout {
    grid-template-columns: 1fr;
  }

  .main-content {
    grid-row: 1;
  }

  .side-bar,
  .sidebar,
  .guide-aside,
  .layout-aside {
    grid-row: 2;
  }

  .inner-main {
    padding: 24px 16px 40px;
  }

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

  .path-grid,
  .topic-grid,
  .guide-steps,
  .step-cards,
  .feature-grid,
  .era-theme-grid {
    grid-template-columns: 1fr;
  }

  .era-timeline {
    grid-template-columns: 1fr;
  }

  .era-timeline::before {
    display: none;
  }

  .era-node::before {
    display: none;
  }

  .era-node {
    padding: 16px;
  }

  .era-period {
    padding-top: 0;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .feedback-inner,
  .feedback-banner-content,
  .entry-bar-inner {
    flex-direction: column;
    text-align: center;
  }

  .map-overview-block {
    grid-template-columns: 1fr;
  }

  .map-figure img {
    height: 180px;
  }

  .topic-grid-section .topic-card {
    flex-direction: column;
  }

  .topic-grid-section .topic-figure {
    width: 100%;
  }

  .topic-grid-section .topic-figure img {
    height: 180px;
    min-height: 0;
  }

  .channel-card {
    flex-direction: column;
  }

  .channel-card-media {
    width: 100%;
    height: 160px;
  }

  .era-archive-grid {
    grid-template-columns: 1fr;
  }

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

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

  .verify-step {
    flex-direction: column;
    gap: 8px;
  }

  .verify-step::before {
    font-size: 18px;
  }

  .page-entry-item {
    flex-direction: column;
    gap: 4px;
  }

  .entry-link {
    min-width: 0;
  }

  .related-links {
    padding: 16px var(--container-padding) 0;
  }

  .hero-section {
    padding-top: 24px;
  }

  .hero-map {
    padding: 20px;
  }

  .hero-channels {
    padding: 20px;
  }

  .error-panel {
    padding: 32px 24px;
  }

  .error-code {
    font-size: 56px;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 15px;
  }

  .brand-name {
    font-size: 19px;
  }

  .brand-tagline {
    font-size: 11px;
  }

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

  .section-title {
    font-size: 20px;
  }

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

  .footer-inner {
    grid-template-columns: 1fr;
  }

  .footer-brand {
    grid-column: auto;
  }

  .channel-card-media {
    height: 140px;
  }

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

  .map-figure img {
    height: 140px;
  }

  .content-media img {
    height: 160px;
  }

  .process-figure img {
    height: 150px;
  }

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

  .topic-figure img {
    height: 150px;
  }

  .theme-image {
    height: 120px;
  }

  .feedback-inner,
  .feedback-banner-content,
  .entry-bar-inner {
    padding: 24px 20px;
  }

  .feedback-link,
  .feedback-banner-link,
  .entry-link {
    width: 100%;
    text-align: center;
  }

  .error-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    text-align: center;
  }
}