/* ==========================================================================
   光棍视频 · bjhsgjs.com
   数据新闻风样式表
   分组：base / layout / components / pages / responsive
   ========================================================================== */

/* ==========================================================================
   base —— 变量、重置、排版、全站骨架
   ========================================================================== */

:root {
  --c-text: #1c2229;
  --c-text-sub: #5a6572;
  --c-bg: #f7f8fa;
  --c-card: #ffffff;
  --c-line: #dfe3e8;
  --c-line-soft: #eceff2;
  --c-accent: #1f5f8b;
  --c-accent-dark: #17496b;
  --c-data: #b4531f;
  --c-focus: #1f5f8b;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Menlo, Consolas, "Liberation Mono", "Courier New", monospace;
  --radius: 6px;
  --radius-sm: 4px;
  --wrap: 1120px;
  --shadow-card: 0 1px 2px rgba(28, 34, 41, 0.05);
  --shadow-hover: 0 3px 10px rgba(28, 34, 41, 0.09);
}

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

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

body {
  margin: 0;
  padding: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
}

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

h1 {
  font-size: 32px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 17px;
}

p {
  margin: 0 0 12px;
}

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

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

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

a {
  color: var(--c-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color 0.15s ease, font-weight 0.15s ease;
}

a:hover {
  color: var(--c-accent-dark);
  font-weight: 700;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--c-focus);
  outline-offset: 2px;
}

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

button {
  font: inherit;
  color: inherit;
}

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

/* 全站骨架：页头 / 主导航 / 主区 / 页脚 ---------------------------------- */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: var(--c-card);
  border-bottom: 1px solid var(--c-line);
}

.header-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
  min-height: 62px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  flex: 0 0 auto;
  font-size: 18px;
  font-weight: 700;
  color: var(--c-text);
  text-decoration: none;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand:hover {
  color: var(--c-accent);
  font-weight: 700;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  padding: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  background: var(--c-card);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--c-text);
  border-radius: 1px;
}

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 22px;
}

.nav-group-item {
  display: block;
}

.nav-link {
  display: inline-block;
  padding: 6px 0;
  font-size: 15px;
  color: var(--c-text-sub);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.nav-link:hover {
  color: var(--c-text);
  font-weight: 700;
}

.nav-link.is-current {
  color: var(--c-accent);
  font-weight: 700;
  border-bottom-color: var(--c-accent);
}

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

.inner-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 24px 24px 56px;
}

.site-footer {
  background: var(--c-card);
  border-top: 1px solid var(--c-line);
  color: var(--c-text-sub);
  font-size: 14px;
}

.footer-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 32px 24px 20px;
  display: grid;
  grid-template-columns: minmax(220px, 1fr) minmax(0, 1.6fr);
  gap: 28px 48px;
}

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

.footer-brand {
  margin-bottom: 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
}

.footer-desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--c-text-sub);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px 24px;
  min-width: 0;
}

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

.footer-group-title {
  margin-bottom: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-link {
  font-size: 13.5px;
  color: var(--c-text-sub);
  text-decoration: none;
}

.footer-link:hover {
  color: var(--c-accent);
  font-weight: 700;
}

.footer-bottom {
  border-top: 1px solid var(--c-line-soft);
}

.footer-copy {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 14px 24px 20px;
  font-size: 13px;
  color: var(--c-text-sub);
}

/* ==========================================================================
   layout —— 页面容器、面包屑、标题区、通用内容块
   ========================================================================== */

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 32px;
  align-items: start;
}

.sidebar-left .page-layout {
  grid-template-columns: 300px minmax(0, 1fr);
}

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

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

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

.home-layout {
  display: block;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px 56px;
}

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

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin-bottom: 14px;
  font-size: 13.5px;
  color: var(--c-text-sub);
}

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

.breadcrumb a:hover {
  color: var(--c-accent);
  font-weight: 700;
}

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

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

.page-header {
  padding-bottom: 20px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--c-line);
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--c-text);
  line-height: 1.3;
}

.page-description {
  margin: 12px 0 0;
  max-width: 720px;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.section {
  margin-bottom: 40px;
}

.section:last-child {
  margin-bottom: 0;
}

.section-head {
  margin-bottom: 18px;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--c-text);
}

.section-desc,
.section-intro,
.section-note {
  margin: 8px 0 0;
  max-width: 720px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.section-foot {
  margin: 14px 0 0;
  font-size: 14px;
  color: var(--c-text-sub);
}

.section-body {
  margin: 0 0 12px;
  max-width: 720px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-text);
}

.inline-link {
  color: var(--c-accent);
}

/* ==========================================================================
   components —— 通用组件：按钮、表格、卡片、列表、折叠、记录
   ========================================================================== */

/* 线索说明条 ------------------------------------------------------------- */

.clue-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 24px;
  background: #eef3f7;
  border-bottom: 1px solid var(--c-line);
  font-size: 13.5px;
  color: var(--c-text-sub);
}

.clue-bar.is-hidden {
  display: none;
}

.clue-text {
  flex: 1 1 auto;
  margin: 0;
  min-width: 0;
}

.clue-close {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  padding: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  background: var(--c-card);
  color: var(--c-text-sub);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
}

.clue-close:hover {
  color: var(--c-text);
  border-color: var(--c-text-sub);
}

/* 按钮 ------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

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

.btn-primary:hover {
  background: var(--c-accent-dark);
  border-color: var(--c-accent-dark);
  color: #ffffff;
  font-weight: 700;
}

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

.btn-ghost:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
  font-weight: 700;
}

.btn-plain {
  background: transparent;
  border-color: transparent;
  color: var(--c-accent);
  text-decoration: underline;
  padding-left: 4px;
  padding-right: 4px;
}

.btn-plain:hover {
  color: var(--c-accent-dark);
  font-weight: 700;
}

/* 数据表格 --------------------------------------------------------------- */

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

.data-table {
  min-width: 720px;
  font-size: 15px;
  line-height: 1.6;
}

.table-caption {
  padding: 12px 16px 4px;
  text-align: left;
  font-size: 13px;
  color: var(--c-text-sub);
}

.data-table thead th {
  padding: 12px 16px;
  background: #f2f4f7;
  border-bottom: 1px solid var(--c-line);
  text-align: left;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--c-text-sub);
  white-space: nowrap;
}

.data-table tbody td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--c-line-soft);
  vertical-align: top;
  color: var(--c-text);
}

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

.data-row {
  transition: background 0.15s ease;
}

.data-row:hover {
  background: #f5f8fb;
}

.cell-code,
.channel-code,
.record-date {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-data);
  white-space: nowrap;
}

.cell-name,
.channel-name {
  font-weight: 700;
  color: var(--c-text);
}

.cell-direction,
.cell-topics,
.cell-fields {
  color: var(--c-text-sub);
  font-size: 14.5px;
}

.row-link,
.cell-link,
.cell-link a {
  white-space: nowrap;
}

.row-link,
.cell-link a {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-accent);
  text-decoration: none;
}

.row-link:hover,
.cell-link a:hover {
  color: var(--c-accent-dark);
  text-decoration: underline;
}

/* 专题卡片 --------------------------------------------------------------- */

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

.topic-card {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  transition: box-shadow 0.18s ease, border-color 0.18s ease;
}

.topic-card:hover {
  border-color: #c6d2dc;
  box-shadow: var(--shadow-hover);
}

.topic-figure,
.topic-cover {
  margin: 0;
  background: #e9edf1;
}

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

.topic-body {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px 18px;
  min-width: 0;
}

.topic-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--c-text);
}

.topic-name a {
  color: inherit;
  text-decoration: none;
}

.topic-name a:hover {
  color: var(--c-accent);
  font-weight: 700;
}

.topic-meta,
.topic-channels,
.topic-composition {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--c-text-sub);
}

.topic-meta {
  font-family: var(--font-mono);
  color: var(--c-data);
}

.topic-desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--c-text-sub);
}

.topic-link {
  align-self: flex-start;
  margin-top: 4px;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-accent);
  text-decoration: none;
}

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

/* 字段定义列表 ----------------------------------------------------------- */

.field-list {
  display: grid;
  grid-template-columns: minmax(96px, max-content) minmax(0, 1fr);
  gap: 0;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-card);
  overflow: hidden;
}

.field-term,
.field-name {
  padding: 11px 14px;
  border-bottom: 1px solid var(--c-line-soft);
  background: #f2f4f7;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
}

.field-def,
.field-desc {
  padding: 11px 14px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--c-text-sub);
}

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

.field-note {
  margin: 10px 0 0;
  font-size: 13.5px;
  color: var(--c-text-sub);
}

/* 通用相关入口列表 ------------------------------------------------------- */

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

.related-item {
  min-width: 0;
}

.related-link {
  display: block;
  padding: 14px 16px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-accent);
  text-decoration: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.related-link:hover {
  border-color: var(--c-accent);
  color: var(--c-accent-dark);
  box-shadow: var(--shadow-card);
  font-weight: 700;
}

.related-desc {
  display: block;
  margin-top: 6px;
  padding: 0 2px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--c-text-sub);
}

/* 折叠组件（指南页） ----------------------------------------------------- */

.field-accordion,
.pitfall-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.field-item,
.pitfall-item {
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.field-summary,
.pitfall-summary {
  position: relative;
  padding: 14px 44px 14px 16px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--c-text);
  cursor: pointer;
  list-style: none;
}

.field-summary::-webkit-details-marker,
.pitfall-summary::-webkit-details-marker {
  display: none;
}

.field-summary::after,
.pitfall-summary::after {
  content: "展开";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 13px;
  font-weight: 400;
  color: var(--c-accent);
}

.field-item[open] .field-summary::after,
.pitfall-item[open] .pitfall-summary::after {
  content: "收起";
}

.field-item[open] .field-summary,
.pitfall-item[open] .pitfall-summary {
  border-bottom: 1px solid var(--c-line-soft);
}

.field-body,
.field-misread,
.pitfall-body,
.pitfall-action {
  margin: 0;
  padding: 12px 16px 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.field-misread,
.pitfall-action {
  padding-bottom: 14px;
  color: var(--c-data);
}

.field-item[open] .field-body:last-child,
.field-item[open] .field-misread:last-child,
.pitfall-item[open] .pitfall-body:last-child,
.pitfall-item[open] .pitfall-action:last-child {
  padding-bottom: 14px;
}

/* 通用 figure 约束 ------------------------------------------------------- */

.section-figure,
.guide-figure,
.records-figure {
  margin: 0 0 18px;
  overflow: hidden;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: #e9edf1;
}

.section-figure img,
.guide-figure img,
.records-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.figure-caption,
.records-figure-caption,
.guide-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--c-line-soft);
  background: var(--c-card);
  font-size: 13px;
  color: var(--c-text-sub);
}

/* ==========================================================================
   pages —— 首页与各内页模块
   ========================================================================== */

/* 首页：左右不对称首屏 --------------------------------------------------- */

.hero {
  padding: 32px 0 40px;
}

.hero-inner {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.hero-aside {
  min-width: 0;
  padding: 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.hero-aside-title {
  padding-bottom: 8px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-text);
}

.channel-index {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-bottom: 18px;
}

.channel-index-item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 6px 0;
  border-bottom: 1px dashed var(--c-line-soft);
  font-size: 14.5px;
  color: var(--c-text);
}

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

.channel-index-item .channel-code {
  flex: 0 0 auto;
}

.channel-index-item .channel-name {
  min-width: 0;
}

.hero-field-title {
  padding-bottom: 8px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-text);
}

.field-quick {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-quick-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-text-sub);
}

.field-quick-item .field-name {
  flex: 0 0 auto;
  padding: 0;
  border: none;
  background: none;
  color: var(--c-data);
  font-family: var(--font-mono);
  font-size: 13.5px;
}

.field-quick-item .field-note {
  margin: 0;
  min-width: 0;
}

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

.hero-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-text);
}

.hero-lead {
  margin: 14px 0 0;
  max-width: 720px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-text-sub);
}

.hero-figure {
  margin: 20px 0 0;
  overflow: hidden;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: #e9edf1;
}

.hero-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

.hero-caption {
  padding: 10px 14px;
  border-top: 1px solid var(--c-line-soft);
  background: var(--c-card);
  font-size: 13px;
  color: var(--c-text-sub);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* 首页：字段含义 + 浏览顺序两栏 ------------------------------------------ */

.field-guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}

.field-column,
.order-column {
  min-width: 0;
}

.column-title {
  margin-bottom: 12px;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
}

.order-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  counter-reset: order-step;
}

.order-item {
  position: relative;
  padding: 12px 14px 12px 46px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--c-text-sub);
  counter-increment: order-step;
}

.order-item::before {
  content: counter(order-step);
  position: absolute;
  left: 14px;
  top: 12px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #eef3f7;
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 22px;
  text-align: center;
}

.order-step {
  display: block;
  margin-bottom: 2px;
  font-size: 14.5px;
  font-weight: 700;
  color: var(--c-text);
}

.order-text {
  display: block;
}

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

/* 首页：整理记录速览 ----------------------------------------------------- */

.record-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.record-group {
  min-width: 0;
  padding: 16px 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.record-month {
  padding-bottom: 8px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-text);
  font-family: var(--font-mono);
}

.record-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.record-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 12px;
  border-left: 2px solid var(--c-line);
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-text-sub);
}

.record-item .record-date {
  font-size: 13px;
}

.record-text {
  display: block;
}

/* 首页：站内栏目索引 ----------------------------------------------------- */

.index-columns {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.index-col {
  min-width: 0;
  padding: 16px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.index-col:hover {
  border-color: #c6d2dc;
  box-shadow: var(--shadow-card);
}

.index-name {
  margin-bottom: 6px;
  font-size: 15px;
  font-weight: 700;
}

.index-link {
  color: var(--c-accent);
  text-decoration: none;
}

.index-link:hover {
  color: var(--c-accent-dark);
  text-decoration: underline;
  font-weight: 700;
}

.index-desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--c-text-sub);
}

/* 频道分类页 ------------------------------------------------------------- */

.section-channels-table .data-table {
  min-width: 760px;
}

.section-direction-notes .note-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.note-item {
  min-width: 0;
  padding: 16px 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.note-title {
  margin-bottom: 6px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--c-text);
}

.note-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.section-fields {
  min-width: 0;
  padding: 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.section-fields .field-list {
  border: none;
  border-radius: 0;
  box-shadow: none;
}

.section-fields .field-name,
.section-fields .field-desc {
  padding: 10px 0;
}

.section-fields .field-name {
  background: none;
  color: var(--c-data);
  font-family: var(--font-mono);
  font-size: 13.5px;
}

/* 专题片单页 ------------------------------------------------------------- */

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

.coverage-section .coverage-table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-card);
  box-shadow: var(--shadow-card);
}

.coverage-table {
  min-width: 640px;
  font-size: 15px;
  line-height: 1.6;
}

.coverage-caption {
  padding: 12px 16px 4px;
  text-align: left;
  font-size: 13px;
  color: var(--c-text-sub);
}

.coverage-table thead th {
  padding: 12px 16px;
  background: #f2f4f7;
  border-bottom: 1px solid var(--c-line);
  text-align: left;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--c-text-sub);
  white-space: nowrap;
}

.coverage-table tbody td {
  padding: 13px 16px;
  border-bottom: 1px solid var(--c-line-soft);
  vertical-align: top;
  font-size: 14.5px;
  color: var(--c-text-sub);
}

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

.coverage-table tbody tr:hover {
  background: #f5f8fb;
}

.coverage-table tbody td:first-child {
  font-weight: 700;
  color: var(--c-text);
}

.coverage-note {
  margin: 14px 0 0;
  font-size: 14px;
  color: var(--c-text-sub);
}

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

.relation-item {
  padding: 16px 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-left: 3px solid var(--c-accent);
  border-radius: var(--radius);
}

.relation-heading {
  margin-bottom: 6px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--c-text);
}

.relation-diff {
  margin: 0 0 6px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.relation-advice {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-data);
}

/* 浏览指引页 ------------------------------------------------------------- */

.steps-track {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.step-item {
  position: relative;
  min-width: 0;
  padding: 18px 16px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.step-index {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 10px;
  border-radius: 999px;
  background: #eef3f7;
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 12.5px;
}

.step-name {
  margin-bottom: 6px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--c-text);
}

.step-body,
.step-check {
  margin: 0 0 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-sub);
}

.step-check {
  color: var(--c-data);
}

.step-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 700;
  color: var(--c-accent);
  text-decoration: none;
}

.step-link:hover {
  color: var(--c-accent-dark);
  text-decoration: underline;
}

/* 整理记录页 ------------------------------------------------------------- */

.layout-shell {
  display: block;
}

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

.records-archive,
.records-scope,
.records-caliber {
  margin-bottom: 36px;
  min-width: 0;
}

.records-archive:last-child,
.records-scope:last-child,
.records-caliber:last-child {
  margin-bottom: 0;
}

.records-archive .record-month {
  padding: 16px 18px;
  margin-bottom: 16px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.records-archive .record-month:last-child {
  margin-bottom: 0;
}

.record-month-title {
  padding-bottom: 10px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
  font-family: var(--font-mono);
}

.records-archive .record-list {
  gap: 14px;
}

.records-archive .record-item {
  padding-left: 14px;
  border-left: 2px solid var(--c-accent);
  gap: 4px;
}

.record-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin: 0;
}

.record-tag {
  display: inline-block;
  padding: 1px 8px;
  border-radius: var(--radius-sm);
  background: #f5ece3;
  color: var(--c-data);
  font-size: 12.5px;
}

.record-body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.scope-table {
  min-width: 560px;
  font-size: 15px;
  line-height: 1.6;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-card);
  overflow: hidden;
}

.scope-table-caption {
  padding: 12px 16px 4px;
  text-align: left;
  font-size: 13px;
  color: var(--c-text-sub);
}

.scope-table thead th {
  padding: 12px 16px;
  background: #f2f4f7;
  border-bottom: 1px solid var(--c-line);
  text-align: left;
  font-size: 13.5px;
  font-weight: 700;
  color: var(--c-text-sub);
  white-space: nowrap;
}

.scope-table tbody td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--c-line-soft);
  vertical-align: top;
  font-size: 14.5px;
  color: var(--c-text-sub);
}

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

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

.caliber-item {
  padding: 14px 16px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.caliber-name {
  margin-bottom: 4px;
  font-size: 15px;
  font-weight: 700;
  color: var(--c-text);
}

.caliber-body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.records-aside {
  min-width: 0;
  padding: 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}

.aside-title {
  padding-bottom: 8px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--c-line-soft);
  font-size: 16px;
  font-weight: 700;
  color: var(--c-text);
}

.aside-text {
  margin: 0 0 12px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-sub);
}

.aside-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}

.aside-item {
  padding-left: 12px;
  border-left: 2px solid var(--c-line);
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-sub);
}

/* 404 页 ----------------------------------------------------------------- */

.error-main {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 48px 24px 64px;
}

.error-intro {
  max-width: 720px;
  padding-bottom: 28px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--c-line);
}

.error-code {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--c-data);
}

.error-intro h1 {
  margin-bottom: 12px;
  font-size: 32px;
  font-weight: 700;
  color: var(--c-text);
}

.error-text {
  margin: 0 0 10px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-text-sub);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.error-hints {
  min-width: 0;
}

.error-hints h2 {
  margin-bottom: 16px;
  font-size: 22px;
  font-weight: 700;
}

.error-hint-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.error-hint-item {
  min-width: 0;
  padding: 16px 18px;
  background: var(--c-card);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.error-hint-item h3 {
  margin-bottom: 6px;
  font-size: 15.5px;
  font-weight: 700;
}

.error-hint-item p {
  margin: 0 0 10px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--c-text-sub);
}

.error-hint-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-accent);
  text-decoration: none;
}

.error-hint-link:hover {
  color: var(--c-accent-dark);
  text-decoration: underline;
}

/* ==========================================================================
   responsive —— 960px / 640px 断点
   ========================================================================== */

@media (max-width: 960px) {
  .header-inner {
    gap: 16px;
    flex-wrap: wrap;
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .nav-toggle {
    display: flex;
  }

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

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0 4px;
    border-top: 1px solid var(--c-line-soft);
  }

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

  .nav-group-item {
    width: 100%;
  }

  .nav-link {
    display: block;
    padding: 12px 4px;
    border-bottom: 1px solid var(--c-line-soft);
  }

  .nav-link.is-current {
    border-bottom-color: var(--c-line-soft);
    box-shadow: inset 3px 0 0 var(--c-accent);
    padding-left: 12px;
  }

  .page-layout,
  .layout-shell .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }

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

  .sidebar-left .page-layout > .site-main,
  .sidebar-left .page-layout > main,
  .sidebar-left .page-layout > .sidebar {
    order: initial;
  }

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

  .hero-aside {
    order: 2;
  }

  .hero-main {
    order: 1;
  }

  .field-guide-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }

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

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

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

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

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

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

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

@media (max-width: 640px) {
  body {
    font-size: 15.5px;
  }

  h1,
  .hero-title,
  .page-title,
  .error-intro h1 {
    font-size: 26px;
  }

  h2,
  .section-title,
  .error-hints h2 {
    font-size: 20px;
  }

  h3,
  .topic-name,
  .column-title,
  .aside-title {
    font-size: 16px;
  }

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

  .clue-bar {
    padding: 10px 16px;
  }

  .clue-text {
    font-size: 13px;
  }

  .hero {
    padding: 22px 0 30px;
  }

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

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

  .topic-figure img,
  .topic-cover img {
    height: 170px;
  }

  .section-figure img,
  .guide-figure img,
  .records-figure img {
    height: 190px;
  }

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

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

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

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

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

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

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

  .field-term,
  .field-name {
    border-bottom: none;
    padding-bottom: 2px;
  }

  .field-def,
  .field-desc {
    padding-top: 0;
  }

  .section-fields .field-name,
  .section-fields .field-desc {
    padding: 6px 0;
  }

  .data-table,
  .section-channels-table .data-table,
  .coverage-table,
  .scope-table {
    min-width: 560px;
  }

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

@media (max-width: 400px) {
  .index-columns {
    grid-template-columns: minmax(0, 1fr);
  }

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

/* 滚动出现动效：仅作为增强，初始态始终可见 ------------------------------- */

@media (prefers-reduced-motion: no-preference) {
  .section,
  .hero-inner,
  .topic-card,
  .record-group {
    animation: fade-rise 0.4s ease both;
  }
}

@keyframes fade-rise {
  from {
    transform: translateY(6px);
  }

  to {
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .section,
  .hero-inner,
  .topic-card,
  .record-group {
    animation: none;
  }
}