/* ==========================================================================
   基础样式 · 字体、颜色、重置
   ========================================================================== */

:root {
  --bg-page: #F3F5F7;
  --bg-panel: #FFFFFF;
  --bg-tint: #E8F0F8;
  --text-body: #1F2933;
  --text-muted: #5E6B78;
  --text-heading: #123A62;
  --link: #1F5FA8;
  --link-hover: #123A62;
  --line: #D5DDE6;
  --line-soft: #E4EAF0;
  --note: #8A5A00;
  --focus: #2F7DC0;
  --radius: 6px;
  --radius-sm: 4px;
  --shell: 1120px;
  --prose: 760px;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-mono: "SFMono-Regular", "Menlo", "Consolas", monospace;
}

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

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

body,
h1, h2, h3, h4,
p, figure, figcaption, blockquote,
ul, ol, dl, dd,
table, th, td {
  margin: 0;
  padding: 0;
}

ul, ol {
  list-style: none;
}

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

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

a:hover,
a:focus-visible {
  color: var(--link-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

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

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

/* ==========================================================================
   布局骨架 · site-body / header / main / footer
   ========================================================================== */

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

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

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

.inner-main {
  padding-top: 20px;
}

/* 页头 */

.site-header {
  background-color: var(--bg-panel);
  border-bottom: 1px solid var(--line);
}

.header-toolbar {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 8px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--line-soft);
}

.toolbar-slogan {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.5;
}

.toolbar-link {
  font-size: 13px;
  line-height: 1.5;
  white-space: nowrap;
}

.header-main {
  position: relative;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 14px 24px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 20px;
}

.brand {
  grid-column: 2;
  justify-self: center;
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-heading);
  text-align: center;
  white-space: nowrap;
}

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

.site-nav,
.nav-secondary {
  min-width: 0;
}

.site-nav {
  grid-column: 1;
  justify-self: start;
}

.nav-secondary {
  grid-column: 3;
  justify-self: end;
}

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

.nav-list a {
  display: inline-block;
  padding: 8px 10px;
  font-size: 15px;
  line-height: 1.4;
  color: var(--text-body);
  border-radius: var(--radius-sm);
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--link);
  background-color: var(--bg-tint);
  text-decoration: none;
}

.nav-list a.is-current {
  color: var(--text-heading);
  font-weight: 700;
  background-color: var(--bg-tint);
}

.nav-toggle {
  display: none;
  grid-column: 3;
  justify-self: end;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background-color: var(--bg-panel);
  position: relative;
}

.nav-toggle::before,
.nav-toggle::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  height: 2px;
  background-color: var(--text-heading);
}

.nav-toggle::before {
  top: 16px;
  box-shadow: 0 6px 0 var(--text-heading);
}

.nav-toggle::after {
  bottom: 15px;
}

.nav-mobile {
  display: none;
  border-top: 1px solid var(--line-soft);
  background-color: var(--bg-panel);
}

.nav-mobile-list {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 8px 16px 16px;
}

.nav-mobile-list a {
  display: block;
  padding: 12px 8px;
  font-size: 16px;
  color: var(--text-body);
  border-bottom: 1px solid var(--line-soft);
}

.nav-mobile-list li:last-child a {
  border-bottom: 0;
}

.nav-mobile-list a:hover,
.nav-mobile-list a:focus-visible {
  color: var(--link);
  text-decoration: none;
}

.nav-mobile-list a.is-current {
  color: var(--text-heading);
  font-weight: 700;
}

/* 内页通用：面包屑 / 页面标题区 */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 4px 0 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

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

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
  color: var(--link);
}

.breadcrumb-sep {
  color: var(--line);
  font-family: var(--font-mono);
}

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

.page-header {
  padding-bottom: 4px;
}

.page-title {
  font-size: 34px;
  line-height: 1.25;
  font-weight: 700;
  color: var(--text-heading);
  letter-spacing: 0;
}

.page-lead {
  max-width: var(--prose);
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-muted);
}

.inner-main > .page-title,
.page-shell .page-title {
  padding-bottom: 18px;
}

/* 页脚 */

.site-footer {
  flex-shrink: 0;
  margin-top: 40px;
  background-color: var(--bg-panel);
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

.footer-grid {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 40px 24px 28px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
}

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

.footer-title {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text-heading);
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
  margin-bottom: 10px;
}

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

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

.footer-list a {
  font-size: 14px;
  color: var(--text-muted);
}

.footer-list a:hover,
.footer-list a:focus-visible {
  color: var(--link);
}

.footer-bottom {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 16px 24px 24px;
  border-top: 1px solid var(--line-soft);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 20px;
}

.footer-copy {
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
}

.footer-nav a {
  font-size: 13px;
  color: var(--text-muted);
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
  color: var(--link);
}

/* ==========================================================================
   通用组件 · 区块标题 / 面板 / 表格 / 版本记录
   ========================================================================== */

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

.section-head h2 {
  font-size: 22px;
  line-height: 1.35;
  font-weight: 700;
  color: var(--text-heading);
}

.section-desc {
  margin-top: 8px;
  max-width: var(--prose);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.section-note,
.section-lead,
.checklist-intro {
  margin: 8px 0 16px;
  max-width: var(--prose);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.inner-main > section {
  margin-top: 36px;
}

.inner-main > section:first-of-type {
  margin-top: 0;
}

.inner-main h2 {
  font-size: 22px;
  line-height: 1.35;
  font-weight: 700;
  color: var(--text-heading);
}

.inner-main h3 {
  font-size: 17px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--text-heading);
}

.inner-main p {
  margin-top: 8px;
}

.inner-main section > p:first-of-type {
  margin-top: 0;
}

.table-scroll {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.channel-list,
.status-list,
.cross-table,
.adjust-table,
.version-table {
  width: 100%;
  font-size: 15px;
  line-height: 1.6;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
}

.channel-list th,
.channel-list td,
.status-list th,
.status-list td,
.cross-table th,
.cross-table td,
.adjust-table th,
.adjust-table td,
.version-table th,
.version-table td {
  padding: 11px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line-soft);
}

.channel-list thead th,
.status-list thead th,
.cross-table thead th,
.version-table thead th {
  background-color: var(--bg-tint);
  color: var(--text-heading);
  font-weight: 700;
  font-size: 14px;
  white-space: nowrap;
}

.channel-list tbody tr:last-child th,
.channel-list tbody tr:last-child td,
.status-list tbody tr:last-child td,
.cross-table tbody tr:last-child td,
.adjust-table tbody tr:last-child td,
.version-table tbody tr:last-child td {
  border-bottom: 0;
}

.channel-list tbody th {
  font-weight: 700;
  color: var(--text-heading);
  white-space: nowrap;
}

.version-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
}

.version-row > div {
  padding: 14px 16px;
  border-right: 1px solid var(--line-soft);
  min-width: 0;
}

.version-row > div:last-child {
  border-right: 0;
}

.version-row h3 {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 6px;
}

.version-row p {
  font-size: 14px;
  line-height: 1.65;
  color: var(--text-muted);
  margin: 0;
}

.version-no p,
.version-value,
.version-code {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.upgrade-help {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

.upgrade-help a + a {
  margin-left: 16px;
}

.version-note .version-row {
  grid-template-columns: 200px 1fr;
}

.version-note .version-label {
  font-weight: 700;
  color: var(--text-heading);
}

.version-note .version-value {
  color: var(--text-body);
}

/* ==========================================================================
   首页 · 首屏查找入口
   ========================================================================== */

.hero-find-entry {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  grid-template-areas:
    "copy links"
    "media media"
    "inline inline";
  gap: 28px 36px;
  padding: 36px 32px 32px;
  margin-top: 28px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.hero-copy {
  grid-area: copy;
  min-width: 0;
}

.hero-kicker {
  font-size: 13px;
  line-height: 1.6;
  color: var(--note);
  margin-bottom: 10px;
}

.hero-copy h1 {
  font-size: 34px;
  line-height: 1.25;
  font-weight: 700;
  color: var(--text-heading);
  letter-spacing: 0;
}

.hero-lead {
  margin-top: 14px;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.button-primary,
.button-secondary {
  display: inline-block;
  padding: 11px 20px;
  min-height: 44px;
  font-size: 15px;
  line-height: 1.4;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
}

.button-primary {
  background-color: var(--link);
  color: #FFFFFF;
  border-color: var(--link);
}

.button-primary:hover,
.button-primary:focus-visible {
  background-color: var(--text-heading);
  border-color: var(--text-heading);
  color: #FFFFFF;
  text-decoration: none;
}

.button-secondary {
  background-color: var(--bg-panel);
  color: var(--link);
  border-color: var(--line);
}

.button-secondary:hover,
.button-secondary:focus-visible {
  background-color: var(--bg-tint);
  border-color: var(--link);
  color: var(--link);
  text-decoration: none;
}

.hero-links {
  grid-area: links;
  min-width: 0;
  padding: 16px 18px;
  background-color: var(--bg-tint);
  border-radius: var(--radius);
}

.hero-links-title {
  font-size: 14px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text-heading);
  margin-bottom: 10px;
}

.hero-links-title + .channel-tags,
.hero-links-title + .topic-links {
  margin-bottom: 16px;
}

.hero-links-title:last-of-type {
  margin-top: 4px;
}

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

.channel-tags a {
  display: inline-block;
  padding: 6px 12px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--link);
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.channel-tags a:hover,
.channel-tags a:focus-visible {
  border-color: var(--link);
  text-decoration: none;
}

.topic-links li {
  border-bottom: 1px dashed var(--line);
}

.topic-links li:last-child {
  border-bottom: 0;
}

.topic-links a {
  display: block;
  padding: 7px 0;
  font-size: 14px;
  line-height: 1.55;
}

.content-media {
  margin: 0;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--bg-panel);
  overflow: hidden;
}

.content-media-primary {
  grid-area: media;
}

.content-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 16 / 7;
}

.content-media figcaption {
  padding: 10px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
  border-top: 1px solid var(--line-soft);
}

.content-media-inline {
  grid-area: inline;
}

.content-media-inline img {
  aspect-ratio: 16 / 5;
}

/* ==========================================================================
   首页 · 频道索引矩阵
   ========================================================================== */

.channel-matrix {
  margin-top: 40px;
}

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

.channel-card {
  padding: 18px 18px 16px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}

.channel-card:hover {
  border-color: var(--link);
}

.channel-name {
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 8px;
}

.channel-name::before {
  content: "§";
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--link);
  margin-right: 6px;
}

.channel-range {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-body);
}

.channel-related {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

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

/* ==========================================================================
   首页 · 问答主栏 + 侧栏
   ========================================================================== */

.page-layout {
  display: grid;
  gap: 28px;
  margin-top: 40px;
}

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

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

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

.qa-item {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}

.qa-item:hover {
  border-color: var(--link);
}

.qa-question {
  font-size: 16px;
  line-height: 1.5;
  font-weight: 700;
  color: var(--text-heading);
}

.qa-question::before {
  content: "问";
  display: inline-block;
  margin-right: 8px;
  padding: 0 5px;
  font-size: 12px;
  font-weight: 700;
  line-height: 20px;
  color: var(--link);
  background-color: var(--bg-tint);
  border-radius: var(--radius-sm);
  vertical-align: 1px;
}

.qa-summary {
  margin-top: 8px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.qa-more {
  display: inline-block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.6;
}

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

.topic-directory,
.feedback-entry {
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.aside-title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-heading);
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line-soft);
}

.directory-list li {
  border-bottom: 1px dashed var(--line);
}

.directory-list li:last-child {
  border-bottom: 0;
}

.directory-list a {
  display: block;
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.6;
}

.feedback-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

.feedback-link {
  display: inline-block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.6;
}

/* ==========================================================================
   首页 · 索引版本记录 / 下一步入口
   ========================================================================== */

.version-record {
  margin-top: 40px;
}

.version-record .version-row {
  border-radius: var(--radius);
  overflow: hidden;
}

.next-step {
  margin-top: 40px;
}

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

.link-card {
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}

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

.link-card h3 {
  font-size: 17px;
  line-height: 1.4;
  font-weight: 700;
  color: var(--text-heading);
}

.link-card p {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ==========================================================================
   频道目录页
   ========================================================================== */

.channel-intro,
.process-overview,
.prep-note {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 28px;
  align-items: start;
  padding: 22px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.channel-media,
.overview-media,
.prep-media,
.qa-media,
.about-media {
  margin: 0;
  min-width: 0;
}

.channel-media img,
.overview-figure img,
.prep-figure img,
.media-figure img,
.about-media img {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.channel-media figcaption,
.overview-figure figcaption,
.prep-figure figcaption,
.media-figure figcaption,
.media-caption {
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

.channel-copy,
.overview-copy,
.prep-copy,
.qa-copy,
.about-copy {
  min-width: 0;
}

.channel-copy p,
.overview-copy p,
.prep-copy p,
.qa-copy p,
.about-copy p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.channel-table {
  margin-top: 36px;
}

.channel-list td a {
  font-size: 14px;
}

.range-notes {
  margin-top: 36px;
}

.range-notes > .section-note {
  margin-bottom: 16px;
}

.range-notes .range-group {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 12px;
}

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

.range-group h3 {
  margin-bottom: 6px;
}

.range-group p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.range-link {
  font-size: 14px;
}

.choice-advice {
  margin-top: 36px;
}

.advice-list {
  counter-reset: advice;
  padding: 20px 22px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.advice-list li {
  counter-increment: advice;
  position: relative;
  padding-left: 34px;
  margin-bottom: 14px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.advice-list li:last-child {
  margin-bottom: 0;
}

.advice-list li::before {
  content: counter(advice);
  position: absolute;
  left: 0;
  top: 2px;
  width: 22px;
  height: 22px;
  line-height: 22px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--link);
  background-color: var(--bg-tint);
  border-radius: 50%;
}

.advice-list a + a {
  margin-left: 12px;
}

.related-links {
  margin-top: 36px;
  padding: 14px 18px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  background-color: var(--bg-tint);
  border-radius: var(--radius);
  font-size: 14px;
}

.related-links-label {
  font-weight: 700;
  color: var(--text-heading);
}

.related-links-item {
  font-size: 14px;
}

/* ==========================================================================
   专题片单页
   ========================================================================== */

.topics .page-layout,
.page-topics .page-layout {
  grid-template-columns: minmax(0, 1fr) 300px;
  align-items: start;
  margin-top: 0;
}

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

.layout-main .breadcrumb {
  padding-top: 0;
}

.topic-list {
  margin-top: 28px;
}

.topic-item {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 20px;
  padding: 18px;
  margin-bottom: 16px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

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

.topic-item:hover {
  border-color: var(--link);
}

.topic-media {
  margin: 0;
  min-width: 0;
}

.topic-media img {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.topic-media figcaption {
  margin-top: 6px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-muted);
}

.topic-body {
  min-width: 0;
}

.topic-body h3 {
  margin-bottom: 6px;
}

.topic-compose,
.topic-scene,
.topic-relate {
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-body);
}

.topic-scene {
  color: var(--text-muted);
}

.topic-relate {
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-muted);
}

.topic-structure,
.topic-cross {
  margin-top: 32px;
}

.topic-structure p {
  font-size: 15px;
  line-height: 1.75;
}

.cross-table {
  margin-top: 14px;
}

.cross-note {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-muted);
}

.adjust-note {
  margin-top: 32px;
}

.adjust-table {
  margin-top: 12px;
}

.adjust-table th {
  width: 140px;
  font-weight: 700;
  color: var(--text-heading);
  background-color: var(--bg-tint);
  white-space: nowrap;
}

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

.related-channels,
.guide-entry {
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.related-channels h2,
.guide-entry h2 {
  font-size: 16px;
  line-height: 1.4;
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line-soft);
}

.related-list li {
  border-bottom: 1px dashed var(--line);
}

.related-list li:last-child {
  border-bottom: 0;
}

.related-list a {
  display: block;
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.6;
}

.related-more {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
}

.guide-entry p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

.guide-link {
  display: inline-block;
  margin-top: 10px;
  padding: 9px 16px;
  min-height: 44px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--link);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.guide-link:hover,
.guide-link:focus-visible {
  background-color: var(--bg-tint);
  border-color: var(--link);
  text-decoration: none;
}

/* ==========================================================================
   观看指南页 · 纵向流程
   ========================================================================== */

.process-overview {
  grid-template-columns: 320px minmax(0, 1fr);
}

.overview-figure,
.prep-figure {
  margin: 0;
}

.overview-points {
  margin-top: 14px;
  padding-left: 0;
}

.overview-points li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-body);
}

.overview-points li:last-child {
  margin-bottom: 0;
}

.overview-points li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 10px;
  width: 6px;
  height: 6px;
  background-color: var(--link);
  border-radius: 50%;
}

.overview-links {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  font-size: 14px;
}

.step-list {
  margin-top: 36px;
}

.step-items {
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 16px;
}

.step-item {
  counter-increment: step;
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding-left: 56px;
  overflow: hidden;
}

.step-item::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 18px;
  top: 18px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--link);
}

.step-input,
.step-process,
.step-result {
  padding: 18px 18px 18px 0;
  min-width: 0;
}

.step-process,
.step-result {
  padding-left: 18px;
  border-left: 1px solid var(--line-soft);
}

.step-input h3,
.step-process h3,
.step-result h3 {
  font-size: 14px;
  font-weight: 700;
  color: var(--note);
  margin-bottom: 6px;
}

.step-input p,
.step-process p,
.step-result p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.info-recognition {
  margin-top: 36px;
}

.info-fields {
  margin-top: 16px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.info-field {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}

.info-field dt {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 6px;
}

.info-field dd {
  margin: 0;
}

.info-field dd p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.field-link {
  margin-top: 8px;
  font-size: 13px;
}

.status-table {
  margin-top: 36px;
}

.status-list {
  margin-top: 14px;
}

.status-list td:first-child {
  font-weight: 700;
  color: var(--text-heading);
  white-space: nowrap;
}

/* ==========================================================================
   入口核验页 · 双列清单
   ========================================================================== */

.prep-note {
  grid-template-columns: 300px minmax(0, 1fr);
}

.prep-list {
  margin-top: 14px;
  counter-reset: prep;
}

.prep-list li {
  counter-increment: prep;
  position: relative;
  padding-left: 28px;
  margin-bottom: 8px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-body);
}

.prep-list li:last-child {
  margin-bottom: 0;
}

.prep-list li::before {
  content: counter(prep) ".";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--link);
}

.checklist {
  margin-top: 36px;
}

.checklist-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.checklist-col-a,
.checklist-col-b {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

.check-item {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--link);
  border-radius: var(--radius);
  min-width: 0;
}

.check-item h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.check-item p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.exception-log {
  margin-top: 36px;
}

.exception-steps {
  counter-reset: exception;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.exception-step {
  counter-increment: exception;
  position: relative;
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
}

.exception-step h3 {
  font-size: 16px;
  margin-bottom: 8px;
  padding-left: 30px;
}

.exception-step h3::before {
  content: counter(exception);
  position: absolute;
  left: 18px;
  top: 18px;
  width: 22px;
  height: 22px;
  line-height: 22px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--link);
  background-color: var(--bg-tint);
  border-radius: 50%;
}

.exception-step p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-body);
}

/* ==========================================================================
   问题解答页
   ========================================================================== */

.page-shell {
  margin-top: 0;
}

.layout-main-aside {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 28px;
  align-items: start;
  margin-top: 28px;
}

.layout-primary {
  min-width: 0;
}

.qa-intro {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 20px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.qa-intro-links {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-size: 14px;
}

.q-group {
  margin-top: 32px;
}

.q-group-desc {
  margin: 8px 0 14px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-muted);
}

.qa-item summary {
  position: relative;
  padding: 2px 30px 2px 0;
  font-size: 16px;
  line-height: 1.55;
  font-weight: 700;
  color: var(--text-heading);
  cursor: pointer;
  list-style: none;
}

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

.qa-item summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 0;
  width: 22px;
  height: 22px;
  line-height: 20px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 400;
  color: var(--link);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.qa-item[open] summary::after {
  content: "−";
}

.qa-item[open] summary {
  margin-bottom: 8px;
}

.qa-answer {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-body);
  padding-top: 8px;
  border-top: 1px solid var(--line-soft);
}

.qa-answer p + p {
  margin-top: 8px;
}

.qa-directory {
  display: flex;
  flex-direction: column;
  gap: 20px;
  min-width: 0;
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.qa-directory > h2 {
  font-size: 16px;
  line-height: 1.4;
  color: var(--text-heading);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line-soft);
}

.aside-subtitle {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 8px;
}

.topic-anchor-list li {
  border-bottom: 1px dashed var(--line);
}

.topic-anchor-list li:last-child {
  border-bottom: 0;
}

.topic-anchor-list a {
  display: block;
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.6;
}

.feedback-note {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

.aside-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 14px;
}

.usage-note {
  margin-top: 32px;
  padding: 18px 20px;
  background-color: var(--bg-tint);
  border-radius: var(--radius);
}

.usage-note-row {
  margin-top: 12px;
}

.usage-note-row:first-of-type {
  margin-top: 10px;
}

.usage-note-row h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.usage-note-row p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-muted);
}

/* ==========================================================================
   站点说明页
   ========================================================================== */

.about-layout {
  grid-template-columns: minmax(0, 1fr) 280px;
  align-items: start;
  margin-top: 0;
}

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

.about-intro {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 20px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-top: 20px;
}

.about-section {
  margin-top: 32px;
}

.about-section > h2 {
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 14px;
}

.about-position,
.about-audience {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 12px;
}

.about-position:last-child,
.about-audience:last-child {
  margin-bottom: 0;
}

.about-position h3,
.about-audience h3 {
  margin-bottom: 6px;
}

.about-position p,
.about-audience p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.boundary-list {
  counter-reset: boundary;
  padding: 18px 20px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.boundary-list li {
  counter-increment: boundary;
  position: relative;
  padding-left: 30px;
  margin-bottom: 12px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

.boundary-list li:last-child {
  margin-bottom: 0;
}

.boundary-list li::before {
  content: counter(boundary, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--note);
}

.version-table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius);
}

.table-caption {
  caption-side: top;
  padding: 8px 0;
  font-size: 13px;
  text-align: left;
  color: var(--text-muted);
}

.term-aside {
  display: flex;
  flex-direction: column;
  gap: 20px;
  min-width: 0;
  padding: 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-top: 20px;
}

.term-aside .aside-title {
  margin-bottom: 12px;
}

.aside-list li {
  border-bottom: 1px dashed var(--line);
}

.aside-list li:last-child {
  border-bottom: 0;
}

.aside-list a {
  display: block;
  padding: 7px 0;
  font-size: 14px;
  line-height: 1.6;
}

.version-index {
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
}

.term-list {
  margin-top: 16px;
}

.term-item {
  padding: 16px 18px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 12px;
}

.term-item dt {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 6px;
}

.term-item dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-body);
}

/* ==========================================================================
   404 页
   ========================================================================== */

.error-main {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 24px 72px;
}

.error-panel {
  padding: 36px 32px;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: left;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--note);
  margin-bottom: 10px;
}

.error-title {
  font-size: 30px;
  line-height: 1.3;
  font-weight: 700;
  color: var(--text-heading);
}

.error-desc {
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-muted);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.btn {
  display: inline-block;
  padding: 11px 20px;
  min-height: 44px;
  font-size: 15px;
  line-height: 1.4;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--link);
  border-color: var(--link);
  color: #FFFFFF;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background-color: var(--text-heading);
  border-color: var(--text-heading);
  color: #FFFFFF;
  text-decoration: none;
}

.btn-ghost {
  background-color: var(--bg-panel);
  border-color: var(--line);
  color: var(--link);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  background-color: var(--bg-tint);
  border-color: var(--link);
  text-decoration: none;
}

.error-links {
  margin-top: 32px;
}

.error-links-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 12px;
}

.error-link-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.error-link-list a {
  display: block;
  padding: 12px 16px;
  min-height: 44px;
  font-size: 15px;
  line-height: 1.5;
  background-color: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

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

/* ==========================================================================
   响应式 · 960px
   ========================================================================== */

@media (max-width: 960px) {
  .home-main,
  .inner-main {
    padding: 0 18px 52px;
  }

  .header-toolbar,
  .header-main {
    padding-left: 18px;
    padding-right: 18px;
  }

  .footer-grid {
    padding: 32px 18px 24px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }

  .footer-bottom {
    padding: 14px 18px 20px;
  }

  .site-nav,
  .nav-secondary {
    display: none;
  }

  .header-main {
    grid-template-columns: 1fr auto;
    gap: 12px;
  }

  .brand {
    grid-column: 1;
    justify-self: start;
    text-align: left;
    font-size: 18px;
    white-space: normal;
  }

  .nav-toggle {
    display: block;
    grid-column: 2;
  }

  .nav-mobile {
    display: block;
  }

  .nav-mobile[hidden] {
    display: none;
  }

  .hero-find-entry {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
      "copy"
      "links"
      "media"
      "inline";
    padding: 26px 22px;
    gap: 22px;
  }

  .hero-copy h1 {
    font-size: 28px;
  }

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

  .qa-layout,
  .page-topics .page-layout,
  .about-layout,
  .layout-main-aside {
    grid-template-columns: minmax(0, 1fr);
  }

  .qa-aside,
  .related-aside,
  .qa-directory,
  .term-aside {
    margin-top: 4px;
  }

  .topic-directory,
  .feedback-entry,
  .related-channels,
  .guide-entry {
    max-width: none;
  }

  .channel-intro,
  .process-overview,
  .prep-note,
  .qa-intro,
  .about-intro {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

  .channel-media img,
  .overview-figure img,
  .prep-figure img,
  .media-figure img,
  .about-media img {
    aspect-ratio: 16 / 8;
  }

  .topic-item {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: 16px;
  }

  .step-item {
    grid-template-columns: minmax(0, 1fr);
    padding-left: 18px;
    padding-top: 34px;
  }

  .step-item::before {
    top: 14px;
    left: 18px;
  }

  .step-input,
  .step-process,
  .step-result {
    padding: 12px 0 0;
  }

  .step-process,
  .step-result {
    border-left: 0;
    border-top: 1px solid var(--line-soft);
  }

  .step-input {
    padding-top: 0;
  }

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

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

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

  .version-note .version-row {
    grid-template-columns: 160px minmax(0, 1fr);
  }
}

/* ==========================================================================
   响应式 · 640px
   ========================================================================== */

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

  .home-main,
  .inner-main {
    padding: 0 14px 44px;
  }

  .header-toolbar,
  .header-main {
    padding-left: 14px;
    padding-right: 14px;
  }

  .header-toolbar {
    gap: 10px;
  }

  .toolbar-slogan {
    font-size: 12px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .toolbar-link {
    font-size: 12px;
  }

  .brand {
    font-size: 16px;
    line-height: 1.35;
  }

  .page-title,
  .hero-copy h1 {
    font-size: 25px;
    line-height: 1.3;
  }

  .inner-main h2,
  .section-head h2,
  .error-links-title {
    font-size: 19px;
  }

  .inner-main h3 {
    font-size: 16px;
  }

  .page-lead {
    font-size: 15px;
  }

  .hero-find-entry {
    margin-top: 18px;
    padding: 22px 16px;
  }

  .hero-actions {
    gap: 10px;
  }

  .button-primary,
  .button-secondary {
    flex: 1 1 auto;
    text-align: center;
    padding: 11px 14px;
  }

  .channel-grid,
  .link-card-grid,
  .info-fields,
  .checklist-grid,
  .exception-steps,
  .error-link-list,
  .version-record .version-row,
  .version-note .version-row,
  .footer-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .version-row > div {
    border-right: 0;
    border-bottom: 1px solid var(--line-soft);
  }

  .version-row > div:last-child {
    border-bottom: 0;
  }

  .topic-item {
    grid-template-columns: minmax(0, 1fr);
    padding: 14px;
  }

  .topic-media img {
    aspect-ratio: 16 / 9;
  }

  .channel-list,
  .status-list,
  .cross-table,
  .adjust-table,
  .version-table {
    font-size: 14px;
    min-width: 560px;
  }

  .adjust-table th {
    width: 100px;
  }

  .qa-item {
    padding: 14px;
  }

  .qa-question,
  .qa-item summary {
    font-size: 15px;
  }

  .qa-item summary::after {
    top: 1px;
  }

  .error-main {
    padding: 32px 14px 48px;
  }

  .error-panel {
    padding: 24px 18px;
  }

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

  .footer-grid {
    gap: 20px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .related-links {
    padding: 12px 14px;
  }
}