/* ============================================================
   BASE
   ============================================================ */
:root {
  --color-primary: #2C3E50;
  --color-accent: #E67E22;
  --color-bg: #ECF0F1;
  --color-white: #FFFFFF;
  --color-secondary: #34495E;
  --color-text: #2C3E50;
  --color-text-light: #5D6D7E;
  --color-border: #D5DBDB;
  --color-card-bg: #FFFFFF;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --container-width: 1200px;
  --content-max-width: 680px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --shadow-sm: 0 1px 3px rgba(44, 62, 80, 0.08);
  --shadow-md: 0 4px 12px rgba(44, 62, 80, 0.1);
  --transition-base: 0.2s ease;
}

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

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-primary);
  margin-bottom: 0.5em;
}

h1 {
  font-size: 2rem;
}

h2 {
  font-size: 1.5rem;
}

h3 {
  font-size: 1.125rem;
}

p {
  margin-bottom: 1em;
}

/* ============================================================
   LAYOUT
   ============================================================ */
.container,
.header-inner,
.footer-content,
.site-main,
.breadcrumb,
.page-header,
.layout-shell {
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.site-main {
  flex: 1 0 auto;
  padding-top: 32px;
  padding-bottom: 48px;
}

.home-main {
  padding-top: 0;
}

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  padding-top: 8px;
  padding-bottom: 8px;
  gap: 16px;
}

.brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-name {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

.brand-tagline {
  font-size: 0.75rem;
  color: var(--color-text-light);
  line-height: 1.3;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle-icon {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-primary);
  position: relative;
  transition: background-color var(--transition-base);
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 24px;
  height: 2px;
  background-color: var(--color-primary);
  transition: transform var(--transition-base);
}

.nav-toggle-icon::before {
  top: -7px;
}

.nav-toggle-icon::after {
  top: 7px;
}

.site-nav {
  display: block;
}

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

.nav-list li {
  margin: 0;
}

.nav-list a {
  display: block;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  color: var(--color-secondary);
  font-weight: 500;
  font-size: 0.9375rem;
  line-height: 1.4;
  transition: background-color var(--transition-base), color var(--transition-base);
}

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

.nav-list a.is-current {
  background-color: var(--color-primary);
  color: var(--color-white);
}

/* ============================================================
   BREADCRUMB
   ============================================================ */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
  padding-top: 0;
  padding-bottom: 0;
}

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

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

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

.breadcrumb-current {
  color: var(--color-primary);
  font-weight: 500;
}

/* ============================================================
   PAGE HEADER
   ============================================================ */
.page-header {
  margin-bottom: 32px;
  padding-top: 8px;
  padding-bottom: 8px;
}

.page-header .page-title {
  font-size: 2rem;
  margin-bottom: 8px;
}

.page-header .page-description {
  font-size: 1rem;
  color: var(--color-text-light);
  max-width: var(--content-max-width);
  margin-bottom: 0;
}

/* ============================================================
   SECTION TITLE
   ============================================================ */
.section-title {
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 12px;
  position: relative;
  padding-bottom: 8px;
}

.section-title::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background-color: var(--color-accent);
  border-radius: 2px;
  margin-top: 8px;
}

.section-intro {
  color: var(--color-text-light);
  max-width: var(--content-max-width);
  margin-bottom: 24px;
  font-size: 0.9375rem;
}

.section-desc {
  color: var(--color-text-light);
  max-width: var(--content-max-width);
  margin-bottom: 24px;
  font-size: 0.9375rem;
}

/* ============================================================
   LAYOUT SHELL / SIDEBAR
   ============================================================ */
.layout-shell {
  display: grid;
  grid-template-columns: minmax(220px, 260px) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.sidebar-left .layout-shell {
  grid-template-columns: minmax(220px, 260px) minmax(0, 1fr);
}

.sidebar-left {
  display: grid;
  grid-template-columns: minmax(220px, 260px) minmax(0, 1fr);
  gap: 32px;
  align-items: start;
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.sidebar-left > .sidebar,
.sidebar-left > .page-aside {
  grid-column: 1;
  min-width: 0;
}

.sidebar-left > .site-main,
.sidebar-left > .content-area {
  grid-column: 2;
  min-width: 0;
}

.sidebar {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  position: sticky;
  top: 80px;
}

.sidebar-title {
  font-size: 1.125rem;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
  color: var(--color-primary);
}

.year-list,
.category-tree {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.year-list a,
.category-tree a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-secondary);
  font-size: 0.9375rem;
  transition: background-color var(--transition-base), color var(--transition-base);
}

.year-list a:hover,
.category-tree a:hover {
  background-color: var(--color-bg);
  color: var(--color-primary);
}

.sidebar-note {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
  font-size: 0.8125rem;
  color: var(--color-text-light);
}

/* ============================================================
   COMPONENTS: CARDS
   ============================================================ */
.topic-card,
.event-item,
.person-card,
.source-card {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.topic-card:hover,
.event-item:hover,
.person-card:hover,
.source-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

/* ============================================================
   COMPONENTS: TOPIC CARD
   ============================================================ */
.topic-card {
  display: flex;
  flex-direction: column;
}

.topic-media {
  overflow: hidden;
  background-color: var(--color-bg);
  aspect-ratio: 16 / 9;
}

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

.topic-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.topic-title {
  font-size: 1.125rem;
  margin-bottom: 8px;
  color: var(--color-primary);
}

.topic-excerpt {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 16px;
  flex: 1;
}

.topic-link {
  display: inline-block;
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-accent);
  align-self: flex-start;
}

.topic-link:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* ============================================================
   COMPONENTS: TOPICS GRID (首页专题推荐)
   ============================================================ */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

/* ============================================================
   COMPONENTS: PEOPLE CARD (首页人物索引)
   ============================================================ */
.people-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.people-card {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.people-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.people-link {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-decoration: none;
  color: inherit;
}

.people-link img {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 12px;
  background-color: var(--color-bg);
}

.people-link h3 {
  font-size: 1rem;
  margin-bottom: 8px;
  color: var(--color-primary);
}

.people-link p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ============================================================
   COMPONENTS: SOURCE CARD
   ============================================================ */
.source-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.source-card {
  padding: 20px;
}

.source-card-title {
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.source-card p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ============================================================
   COMPONENTS: EVENT ITEM
   ============================================================ */
.event-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  margin-bottom: 12px;
}

.event-thumb {
  width: 120px;
  flex-shrink: 0;
  background-color: var(--color-bg);
  border-radius: var(--radius-sm);
  overflow: hidden;
  aspect-ratio: 3 / 2;
}

.event-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.event-info {
  flex: 1;
  min-width: 0;
}

.event-title {
  font-size: 1rem;
  margin-bottom: 4px;
  color: var(--color-primary);
}

.event-date {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin-bottom: 8px;
  display: block;
}

.event-summary {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ============================================================
   COMPONENTS: EVENT ARCHIVE
   ============================================================ */
.event-archive {
  margin-bottom: 40px;
}

.month-group {
  margin-bottom: 24px;
}

.month-title {
  font-size: 1rem;
  color: var(--color-secondary);
  margin-bottom: 12px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--color-border);
}

/* ============================================================
   COMPONENTS: PERSON CARD (内页人物资料)
   ============================================================ */
.person-card {
  display: flex;
  flex-direction: column;
  padding: 16px;
}

.person-media {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  overflow: hidden;
  background-color: var(--color-bg);
  margin-bottom: 12px;
  flex-shrink: 0;
}

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

.person-body {
  flex: 1;
}

.person-name {
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.person-role {
  font-size: 0.8125rem;
  color: var(--color-accent);
  margin-bottom: 8px;
  display: block;
}

.person-brief {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 8px;
}

.person-events {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ============================================================
   COMPONENTS: PEOPLE CATEGORY
   ============================================================ */
.people-category {
  margin-bottom: 32px;
}

.category-title {
  font-size: 1.125rem;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-border);
}

/* ============================================================
   COMPONENTS: PROFILE LIST
   ============================================================ */
.profile-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.profile-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.profile-main {
  flex: 1;
  min-width: 0;
}

.profile-name {
  font-size: 1.125rem;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.profile-meta {
  font-size: 0.8125rem;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.profile-content {
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

.profile-content p {
  margin-bottom: 8px;
}

.profile-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
  justify-content: flex-start;
  padding-top: 4px;
}

.profile-links a {
  font-size: 0.875rem;
  font-weight: 500;
  white-space: nowrap;
}

/* ============================================================
   COMPONENTS: GUIDE STEPS
   ============================================================ */
.guide-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  margin-bottom: 24px;
}

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

.guide-step .step-number {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.2;
  flex-shrink: 0;
  min-width: 32px;
}

.guide-step .step-content {
  flex: 1;
  min-width: 0;
}

.guide-step .step-content h3 {
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.guide-step .step-content p {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 0;
}

.section-note {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-top: 16px;
}

/* ============================================================
   COMPONENTS: RELATED ENTRY
   ============================================================ */
.related-entry {
  margin-top: 40px;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.related-entry p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

.related-entry a {
  display: inline-block;
  margin-right: 16px;
  font-weight: 500;
}

/* ============================================================
   COMPONENTS: RELATED LINKS (sources)
   ============================================================ */
.related-links {
  margin-top: 40px;
}

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

.related-list li {
  padding: 12px 16px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.related-list a {
  font-weight: 500;
}

/* ============================================================
   COMPONENTS: SUMMARY LINKS (topics)
   ============================================================ */
.summary-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 16px;
}

.summary-links a {
  font-weight: 500;
  padding: 8px 16px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-base), color var(--transition-base);
}

.summary-links a:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

/* ============================================================
   COMPONENTS: PRINCIPLES WRAP (sources)
   ============================================================ */
.principles-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 400px);
  gap: 32px;
  align-items: start;
}

.principles-text {
  max-width: var(--content-max-width);
}

.principles-text p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 1em;
}

.principles-figure {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.principles-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.principles-figure figcaption {
  padding: 12px 16px;
  font-size: 0.8125rem;
  color: var(--color-text-light);
  background-color: var(--color-bg);
}

/* ============================================================
   COMPONENTS: BOUNDARY BLOCK (sources)
   ============================================================ */
.boundary-block {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.boundary-block h3 {
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 12px;
}

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

.boundary-list li {
  padding-left: 20px;
  position: relative;
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

.boundary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 8px;
  background-color: var(--color-accent);
  border-radius: 50%;
}

/* ============================================================
   PAGES: HOME
   ============================================================ */
.brand-section {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 48px 24px;
  margin-bottom: 48px;
}

.layout-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 480px);
  gap: 48px;
  align-items: center;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

.brand-copy {
  max-width: 600px;
}

.brand-copy h1 {
  font-size: 2.25rem;
  margin-bottom: 16px;
  color: var(--color-primary);
}

.positioning-statement {
  font-size: 1.0625rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
  line-height: 1.7;
}

.cta-link {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: background-color var(--transition-base), transform var(--transition-base);
}

.cta-link:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-1px);
}

.brand-figure {
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.brand-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.brand-figure figcaption {
  padding: 12px 16px;
  font-size: 0.8125rem;
  color: var(--color-text-light);
  background-color: var(--color-white);
  border-top: 1px solid var(--color-border);
}

/* 时间线 */
.timeline-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

.timeline-horizontal {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.timeline-node {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 16px;
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: box-shadow var(--transition-base), border-color var(--transition-base);
  position: relative;
}

.timeline-node::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 16px;
  right: 16px;
  height: 3px;
  background-color: var(--color-accent);
  border-radius: 0 0 3px 3px;
  opacity: 0.6;
}

.timeline-node:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent);
}

.timeline-year {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.timeline-desc {
  font-size: 0.8125rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

/* 专题推荐 */
.topics-preview-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

/* 人物资料索引 */
.people-preview-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

/* 资料来源说明 */
.sources-note-section {
  padding: 0 24px 48px;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
}

.sources-text {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  max-width: var(--content-max-width);
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sources-text a {
  font-weight: 600;
}

/* ============================================================
   PAGES: TOPICS
   ============================================================ */
.topic-section {
  margin-bottom: 48px;
}

.topic-section .topic-card {
  margin-bottom: 24px;
  flex-direction: row;
}

.topic-section .topic-media {
  width: 280px;
  flex-shrink: 0;
  aspect-ratio: 16 / 10;
}

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

.topic-summary-section {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 32px;
}

.summary-text {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.summary-text strong {
  color: var(--color-primary);
}

/* ============================================================
   PAGES: PEOPLE
   ============================================================ */
.page-aside {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

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

.aside-title {
  font-size: 1rem;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
}

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

.aside-list a {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-secondary);
  font-size: 0.9375rem;
  transition: background-color var(--transition-base), color var(--transition-base);
}

.aside-list a:hover {
  background-color: var(--color-bg);
  color: var(--color-primary);
}

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

/* ============================================================
   PAGES: SOURCES
   ============================================================ */
.content-section .section-title {
  margin-bottom: 20px;
}

/* ============================================================
   PAGES: 404
   ============================================================ */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
}

.error-section {
  text-align: left;
  max-width: 560px;
  padding: 48px 24px;
}

.error-code {
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 1.75rem;
  margin-bottom: 16px;
}

.error-desc {
  font-size: 1rem;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.error-guide {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.error-btn {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: var(--color-white);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: background-color var(--transition-base);
}

.error-btn:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.error-link {
  display: inline-block;
  padding: 12px 20px;
  color: var(--color-secondary);
  font-weight: 500;
  font-size: 0.9375rem;
}

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

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background-color: var(--color-primary);
  color: var(--color-white);
  margin-top: auto;
  flex-shrink: 0;
}

.footer-content {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 48px;
  padding-top: 40px;
  padding-bottom: 32px;
  align-items: start;
}

.footer-brand {
  max-width: 420px;
}

.footer-slogan {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-white);
}

.footer-desc {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 0;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-top: 4px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.9375rem;
  transition: color var(--transition-base);
}

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

.footer-legal {
  grid-column: 1 / -1;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.footer-legal p {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 4px;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .layout-split {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 380px);
    gap: 32px;
  }

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

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

  .principles-wrap {
    grid-template-columns: 1fr;
  }

  .principles-figure {
    max-width: 480px;
  }

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

  .topic-section .topic-media {
    width: 100%;
    aspect-ratio: 16 / 9;
  }
}

@media (max-width: 900px) {
  .layout-shell {
    grid-template-columns: minmax(200px, 240px) minmax(0, 1fr);
    gap: 24px;
  }

  .sidebar-left {
    grid-template-columns: minmax(200px, 240px) minmax(0, 1fr);
    gap: 24px;
  }
}

@media (max-width: 768px) {
  /* 导航 */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    display: block;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 8px 24px 16px;
    gap: 2px;
  }

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

  .nav-list a {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
  }

  /* 布局 */
  .layout-shell,
  .sidebar-left {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .sidebar-left > .sidebar,
  .sidebar-left > .page-aside,
  .sidebar-left > .site-main,
  .sidebar-left > .content-area {
    grid-column: 1;
  }

  .sidebar,
  .page-aside > .aside-panel {
    position: static;
  }

  .sidebar-left > .page-aside {
    order: -1;
  }

  .sidebar-left > .site-main {
    order: 2;
  }

  /* 首页 */
  .brand-section {
    padding: 32px 16px;
    margin-bottom: 32px;
  }

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

  .brand-copy h1 {
    font-size: 1.75rem;
  }

  .timeline-section,
  .topics-preview-section,
  .people-preview-section,
  .sources-note-section {
    padding-left: 16px;
    padding-right: 16px;
  }

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

  .topics-grid,
  .people-grid,
  .source-grid,
  .guide-steps {
    grid-template-columns: 1fr;
  }

  /* 内页 */
  .site-main {
    padding-top: 24px;
    padding-bottom: 32px;
  }

  .page-header .page-title {
    font-size: 1.625rem;
  }

  .breadcrumb {
    margin-bottom: 16px;
  }

  /* 事件 */
  .event-item {
    flex-direction: column;
  }

  .event-thumb {
    width: 100%;
    aspect-ratio: 16 / 9;
  }

  /* 人物 */
  .profile-item {
    flex-direction: column;
    gap: 16px;
  }

  .profile-links {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 16px;
  }

  /* 页脚 */
  .footer-content {
    grid-template-columns: 1fr;
    gap: 32px;
    padding-top: 32px;
    padding-bottom: 24px;
  }

  .footer-links {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 16px;
  }

  .footer-legal {
    padding-top: 16px;
  }
}

@media (max-width: 480px) {
  .container,
  .header-inner,
  .footer-content,
  .site-main,
  .breadcrumb,
  .page-header,
  .layout-shell,
  .sidebar-left {
    padding-left: 16px;
    padding-right: 16px;
  }

  .brand-tagline {
    display: none;
  }

  .brand-name {
    font-size: 1.25rem;
  }

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

  .profile-item {
    padding: 16px;
  }

  .boundary-block {
    padding: 16px;
  }

  .sources-text {
    padding: 16px;
  }

  .error-section {
    padding: 32px 16px;
  }

  .error-code {
    font-size: 2.25rem;
  }

  .error-actions {
    flex-direction: column;
    align-items: flex-start;
  }
}