/* =========================================================
   秋霞理论电影 biwutech.cn
   1. base
   2. layout
   3. components
   4. pages
   5. responsive
   ========================================================= */

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

:root {
  --color-bg: #ffffff;
  --color-text: #1f2933;
  --color-accent: #2563eb;
  --color-accent-dark: #1d4ed8;
  --color-border: #e5e7eb;
  --color-surface: #f3f4f6;
  --color-muted: #6b7280;
  --color-type-add: #2563eb;
  --color-type-adjust: #b45309;
  --color-type-archive: #6b7280;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --container: 1080px;
  --reading: 820px;
  --header-height: 64px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

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

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

body {
  margin: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 0.5em;
  font-weight: 600;
  line-height: 1.35;
  color: var(--color-text);
}

p {
  margin: 0 0 1em;
}

p:last-child {
  margin-bottom: 0;
}

ul,
ol {
  margin: 0 0 1em;
  padding-left: 1.25em;
}

li {
  margin-bottom: 0.35em;
}

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

a:hover,
a:focus {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

figure {
  margin: 0;
}

figcaption {
  margin-top: 0.5em;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

table {
  border-collapse: collapse;
  width: 100%;
}

th,
td {
  text-align: left;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
}

strong {
  font-weight: 600;
}

/* ---------------- 2. layout ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px 24px;
}

.brand {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand:hover,
.brand:focus {
  color: var(--color-accent);
  text-decoration: none;
}

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

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-list > li {
  margin: 0;
}

.nav-list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  font-size: 15px;
  color: var(--color-text);
  border-radius: var(--radius-md);
  text-decoration: none;
}

.nav-list a:hover,
.nav-list a:focus {
  color: var(--color-accent);
  background-color: var(--color-surface);
  text-decoration: none;
}

.nav-list a.is-current {
  color: var(--color-accent);
  font-weight: 600;
  background-color: var(--color-surface);
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg);
  position: relative;
}

.nav-toggle::before,
.nav-toggle::after {
  content: "";
  position: absolute;
  left: 50%;
  width: 18px;
  height: 2px;
  background-color: var(--color-text);
  transform: translateX(-50%);
}

.nav-toggle::before {
  top: 16px;
}

.nav-toggle::after {
  bottom: 16px;
}

.nav-toggle:hover,
.nav-toggle:focus {
  border-color: var(--color-accent);
}

.site-main {
  display: block;
}

.home-main,
.inner-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px 64px;
}

.top-info-bar {
  margin: 0;
  padding: 10px 24px;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  font-size: 14px;
  color: var(--color-muted);
  text-align: center;
}

.site-footer {
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  margin-top: 0;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 24px 24px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
}

.footer-col {
  min-width: 0;
}

.footer-brand {
  margin: 0 0 12px;
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
}

.footer-about p {
  margin: 0;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.footer-heading {
  margin: 0 0 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-links > li {
  margin: 0 0 8px;
}

.footer-links a {
  font-size: 14px;
  color: var(--color-muted);
  text-decoration: none;
}

.footer-links a:hover,
.footer-links a:focus {
  color: var(--color-accent);
  text-decoration: underline;
}

.footer-copy {
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px 24px 28px;
  font-size: 13px;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
}

/* ---------------- 3. components ---------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  text-decoration: none;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

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

.btn-primary:hover,
.btn-primary:focus {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  color: #ffffff;
  text-decoration: none;
}

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

.btn-ghost:hover,
.btn-ghost:focus {
  color: var(--color-accent);
  border-color: var(--color-accent);
  text-decoration: none;
}

.section-head {
  margin-bottom: 20px;
}

.section-head h2 {
  margin: 0 0 8px;
  font-size: 22px;
}

.section-head p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
  max-width: 720px;
}

.section-title,
.section-note,
.section-intro,
.section-lead {
  margin: 0 0 8px;
}

.section-title,
.inner-main h2 {
  font-size: 22px;
  font-weight: 600;
}

.section-note,
.section-intro,
.section-lead {
  font-size: 15px;
  color: var(--color-muted);
  max-width: 720px;
  margin-bottom: 20px;
}

.section-lead a,
.section-note a {
  color: var(--color-accent);
}

.section-more {
  margin: 20px 0 0;
  font-size: 15px;
}

.section-more a {
  font-weight: 500;
}

.text-link {
  font-size: 15px;
  font-weight: 500;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.data-table,
.channel-table,
.field-table,
.related-table {
  width: 100%;
  min-width: 640px;
  font-size: 14px;
}

.data-table caption,
.table-caption {
  caption-side: top;
  padding: 14px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-muted);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.data-table thead th,
.channel-table thead th,
.field-table thead th,
.related-table thead th {
  padding: 12px 16px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.data-table tbody th,
.data-table tbody td,
.channel-table tbody th,
.channel-table tbody td,
.field-table tbody th,
.field-table tbody td,
.related-table tbody th,
.related-table tbody td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
  line-height: 1.65;
}

.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td,
.channel-table tbody tr:last-child th,
.channel-table tbody tr:last-child td,
.field-table tbody tr:last-child th,
.field-table tbody tr:last-child td,
.related-table tbody tr:last-child th,
.related-table tbody tr:last-child td {
  border-bottom: none;
}

.data-table tbody tr:hover,
.channel-table tbody tr:hover,
.field-table tbody tr:hover,
.related-table tbody tr:hover {
  background-color: var(--color-surface);
}

.field-table tbody th {
  width: 30%;
  font-weight: 600;
  white-space: nowrap;
}

.channel-table tbody th {
  font-weight: 600;
  white-space: nowrap;
}

.record-type {
  display: inline-block;
  padding: 2px 10px;
  font-size: 13px;
  font-weight: 500;
  line-height: 1.6;
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-muted);
  white-space: nowrap;
}

.record-type-add {
  background-color: #e8effd;
  color: var(--color-type-add);
}

.record-type-adjust {
  background-color: #fdf1e3;
  color: var(--color-type-adjust);
}

.record-type-archive {
  background-color: #eceef1;
  color: var(--color-type-archive);
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  padding: 24px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

.breadcrumb a {
  color: var(--color-muted);
  text-decoration: none;
}

.breadcrumb a:hover,
.breadcrumb a:focus {
  color: var(--color-accent);
  text-decoration: underline;
}

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

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

.page-header {
  padding: 16px 0 28px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 36px;
}

.page-title {
  margin: 0 0 10px;
  font-size: 32px;
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text);
}

.page-description {
  margin: 0;
  font-size: 16px;
  color: var(--color-muted);
  max-width: var(--reading);
}

.inner-main > section {
  margin-bottom: 52px;
}

.inner-main > section:last-of-type {
  margin-bottom: 0;
}

/* ---------------- 4. pages ---------------- */

/* 首页 hero */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 40px;
  align-items: start;
  padding: 48px 0 56px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 52px;
}

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

.hero-title {
  margin: 0 0 16px;
  font-size: 32px;
  font-weight: 600;
  line-height: 1.3;
}

.hero-lead {
  margin: 0 0 24px;
  font-size: 17px;
  color: var(--color-muted);
  max-width: 560px;
}

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

.hero-aside {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-figure {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-surface);
}

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

.hero-figure figcaption {
  margin: 0;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.hero-clues {
  list-style: none;
  margin: 0;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.hero-clues > li {
  margin: 0;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
  border-bottom: 1px solid var(--color-border);
}

.hero-clues > li:last-child {
  border-bottom: none;
}

.hero-clues strong {
  display: block;
  margin-bottom: 2px;
  font-size: 15px;
  color: var(--color-text);
}

/* 首页 题材频道总览 */

.channel-overview {
  margin-bottom: 56px;
}

/* 首页 专题片单 */

.collection-cards {
  margin-bottom: 56px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.collection-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
  overflow: hidden;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.collection-card:hover {
  border-color: #c7d2e0;
  box-shadow: 0 1px 6px rgba(31, 41, 51, 0.06);
}

.card-media {
  margin: 0;
  background-color: var(--color-surface);
}

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

.card-title {
  margin: 18px 20px 8px;
  font-size: 18px;
}

.card-desc {
  margin: 0 20px 12px;
  font-size: 15px;
  color: var(--color-muted);
}

.card-meta {
  margin: auto 20px 20px;
  padding-top: 12px;
  font-size: 14px;
  border-top: 1px solid var(--color-border);
}

/* 首页 浏览指引摘要 */

.guide-summary {
  margin-bottom: 56px;
}

.guide-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 32px;
  align-items: start;
}

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

.guide-col h3 {
  margin: 0 0 14px;
  font-size: 17px;
}

.guide-col .field-table {
  min-width: 0;
}

/* 首页 整理记录速览 */

.records-preview {
  margin-bottom: 56px;
}

.records-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.record-group {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.record-month {
  margin: 0 0 14px;
  font-size: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.record-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.record-item {
  margin: 0 0 12px;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.65;
}

.record-item:last-child {
  margin-bottom: 0;
}

.record-item .record-type {
  margin-right: 8px;
}

/* 首页 站内页面索引 */

.page-index {
  margin-bottom: 0;
}

.index-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.index-col {
  min-width: 0;
  padding: 20px;
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
}

.index-col h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.index-col p {
  margin: 0;
  font-size: 14px;
  color: var(--color-muted);
}

/* 内页 题材频道 */

.channel-table-section {
  margin-bottom: 52px;
}

.channel-visual-section {
  margin-bottom: 52px;
}

.channel-visual-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.channel-figure {
  margin: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-surface);
}

.channel-figure img {
  width: 100%;
  height: 170px;
  object-fit: cover;
}

.channel-figure figcaption {
  margin: 0;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.direction-notes-section {
  margin-bottom: 52px;
}

.direction-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.direction-item {
  min-width: 0;
  margin: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.direction-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.direction-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.organization-notes-section {
  margin-bottom: 52px;
}

.organization-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.organization-item {
  min-width: 0;
  padding: 20px;
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
}

.organization-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.organization-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.channel-path-section {
  margin-bottom: 0;
}

.path-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.path-item {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.path-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.path-item p {
  margin: 0 0 12px;
  font-size: 15px;
  color: var(--color-muted);
}

/* 内页 专题片单 */

.collection-list-section {
  margin-bottom: 52px;
}

.collection-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.collection-card .collection-cover {
  margin: 0;
  background-color: var(--color-surface);
}

.collection-cover img {
  width: 100%;
  height: 190px;
  object-fit: cover;
}

.collection-name {
  margin: 18px 20px 8px;
  font-size: 18px;
}

.collection-summary {
  margin: 0 20px 14px;
  font-size: 15px;
  color: var(--color-muted);
}

.collection-meta {
  margin: auto 20px 20px;
  padding-top: 12px;
  border-top: 1px solid var(--color-border);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 12px;
  font-size: 14px;
}

.collection-meta dt {
  color: var(--color-muted);
  white-space: nowrap;
}

.collection-meta dd {
  margin: 0;
}

.topic-notes-section {
  margin-bottom: 52px;
}

.topic-note-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.topic-note {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.topic-note-name {
  margin: 0 0 8px;
  font-size: 16px;
}

.topic-note p {
  margin: 0 0 8px;
  font-size: 15px;
  color: var(--color-muted);
}

.topic-note-order {
  margin: 0;
  font-size: 14px;
  color: var(--color-text);
}

.related-directions-section {
  margin-bottom: 0;
}

.related-table {
  min-width: 560px;
}

.related-hint {
  margin: 16px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

.related-hint a {
  margin-right: 12px;
}

/* 内页 浏览指引 */

.guide-fields {
  margin-bottom: 52px;
}

.guide-media {
  margin: 0 0 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-surface);
}

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

.guide-media figcaption {
  margin: 0;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.guide-fields .field-table {
  min-width: 520px;
}

.guide-boundary {
  margin-bottom: 52px;
}

.boundary-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.boundary-item {
  min-width: 0;
  margin: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.boundary-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.boundary-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.guide-steps {
  margin-bottom: 52px;
}

.step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.step-item {
  min-width: 0;
  margin: 0;
  padding: 20px;
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
}

.step-index {
  display: inline-block;
  min-width: 28px;
  margin-bottom: 10px;
  padding: 2px 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.step-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.step-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.guide-faq {
  margin-bottom: 52px;
}

.faq-list {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
  overflow: hidden;
}

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

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

.faq-item summary {
  padding: 16px 48px 16px 20px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  position: relative;
}

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

.faq-item summary::after {
  content: "";
  position: absolute;
  right: 22px;
  top: 50%;
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--color-muted);
  border-bottom: 2px solid var(--color-muted);
  transform: translateY(-70%) rotate(45deg);
  transition: transform 0.15s ease;
}

.faq-item[open] summary::after {
  transform: translateY(-30%) rotate(-135deg);
}

.faq-item summary:hover,
.faq-item summary:focus {
  color: var(--color-accent);
}

.faq-item p {
  margin: 0;
  padding: 0 20px 18px;
  font-size: 15px;
  color: var(--color-muted);
}

.guide-links {
  margin-bottom: 0;
}

.related-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.related-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-width: 0;
  margin: 0;
  padding: 14px 18px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
  font-size: 15px;
}

.related-item span {
  font-size: 14px;
  color: var(--color-muted);
  white-space: nowrap;
}

/* 内页 整理记录 */

.records-timeline {
  margin-bottom: 52px;
}

.records-media {
  margin: 0 0 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-surface);
}

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

.records-media figcaption {
  margin: 0;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
}

.timeline-group {
  margin-bottom: 32px;
  padding-left: 20px;
  border-left: 2px solid var(--color-border);
}

.timeline-group:last-child {
  margin-bottom: 0;
}

.timeline-month {
  margin: 0 0 14px;
  font-size: 17px;
}

.timeline-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.timeline-item {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.65;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item p {
  margin: 0;
  flex: 1 1 240px;
  min-width: 0;
}

.change-type-notes {
  margin-bottom: 52px;
}

.change-type-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.change-type-item {
  min-width: 0;
  margin: 0;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
}

.change-type-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.change-type-item p {
  margin: 0;
  font-size: 15px;
  color: var(--color-muted);
}

.archive-notes {
  margin-bottom: 0;
}

.archive-note-list {
  margin: 0 0 16px;
  padding-left: 1.25em;
  font-size: 15px;
  color: var(--color-muted);
}

.archive-note-list li {
  margin-bottom: 8px;
}

.archive-tail {
  margin: 0;
  font-size: 14px;
  color: var(--color-muted);
}

.archive-tail a {
  margin-right: 14px;
}

/* 404 页面 */

.error-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px 88px;
}

.error-intro {
  max-width: 640px;
  margin-bottom: 48px;
}

.error-intro h1 {
  margin: 0 0 16px;
  font-size: 32px;
  font-weight: 600;
}

.error-intro p {
  margin: 0 0 12px;
  font-size: 16px;
  color: var(--color-muted);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.error-hints h2 {
  margin: 0 0 16px;
  font-size: 20px;
}

.error-hint-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.error-hint-list li {
  margin: 0;
  min-width: 0;
}

.error-hint-list a {
  display: flex;
  align-items: center;
  min-height: 56px;
  padding: 12px 18px;
  font-size: 15px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg);
  color: var(--color-text);
  text-decoration: none;
}

.error-hint-list a:hover,
.error-hint-list a:focus {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

/* 内容区滚动出现增强（不影响初始可见性） */

@media (prefers-reduced-motion: no-preference) {
  .home-main > section,
  .inner-main > section {
    animation: fade-up 0.4s ease-out both;
  }

  .home-main > section:nth-of-type(n + 3),
  .inner-main > section:nth-of-type(n + 3) {
    animation: none;
  }
}

@keyframes fade-up {
  from {
    transform: translateY(8px);
  }

  to {
    transform: translateY(0);
  }
}

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

@media (max-width: 1024px) {
  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
    gap: 8px 16px;
  }

  .nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    flex: 1 0 100%;
    margin-left: 0;
    order: 3;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0 12px;
    border-top: 1px solid var(--color-border);
  }

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

  .nav-list a {
    min-height: 48px;
    padding: 0 8px;
    border-radius: var(--radius-sm);
  }

  .home-main,
  .inner-main,
  .error-main {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 32px 0 40px;
    margin-bottom: 40px;
  }

  .hero-title,
  .page-title,
  .error-intro h1 {
    font-size: 24px;
  }

  .hero-lead {
    font-size: 16px;
  }

  .page-header {
    padding: 12px 0 20px;
    margin-bottom: 28px;
  }

  .inner-main > section {
    margin-bottom: 40px;
  }

  .card-grid,
  .collection-grid,
  .guide-columns,
  .records-groups,
  .channel-visual-grid,
  .direction-list,
  .organization-grid,
  .path-grid,
  .topic-note-list,
  .boundary-list,
  .step-list,
  .related-list,
  .change-type-list {
    grid-template-columns: minmax(0, 1fr);
  }

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

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

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
    padding: 32px 16px 16px;
  }

  .footer-copy {
    padding: 16px 16px 24px;
  }

  .collection-meta {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .collection-meta dt {
    margin-top: 6px;
  }

  .timeline-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .related-item {
    flex-wrap: wrap;
  }
}

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

  .brand {
    font-size: 16px;
  }

  .nav-list a {
    font-size: 15px;
  }

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

  .card-media img,
  .collection-cover img {
    height: 160px;
  }

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

  .guide-media img,
  .records-media img {
    height: 170px;
  }

  .hero-actions,
  .error-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }

  .related-item span {
    white-space: normal;
  }

  .archive-tail a,
  .related-hint a {
    display: inline-block;
    margin: 0 12px 8px 0;
  }
}