:root {
  --color-primary: #1f5fd6;
  --color-accent: #f2603c;
  --color-bg: #f7f8fa;
  --color-card: #ffffff;
  --color-text: #1c2430;
  --color-muted: #6b7686;
  --color-line: #e3e7ee;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --shadow-card: 0 1px 2px rgba(28, 36, 48, 0.05);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --container: 1120px;
  --gutter: 24px;
}

/* ===================== base ===================== */

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

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

body {
  margin: 0;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.75;
  font-weight: 400;
}

h1,
h2,
h3,
h4,
p,
figure,
dl,
dd,
ol,
ul {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

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

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

a:hover,
a:focus {
  text-decoration: underline;
}

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

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

/* ===================== layout ===================== */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.site-nav {
  display: flex;
  align-items: center;
}

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

.nav-item {
  display: flex;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  font-size: 14px;
  color: var(--color-text);
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

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

.nav-link.is-current {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: 600;
}

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

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

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

.inner-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px var(--gutter) 40px;
}

.home-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter) 40px;
}

/* ===================== components ===================== */

/* 顶部事实条 */
.top-fact-bar {
  background-color: #eef2fa;
  border-bottom: 1px solid var(--color-line);
}

.top-fact-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.top-fact-bar .top-fact-text {
  font-size: 13px;
  color: var(--color-muted);
  padding: 8px 0;
  line-height: 1.6;
}

/* 品牌标识 */
.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: 19px;
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
}

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

.brand-sub {
  font-size: 12px;
  font-weight: 400;
  color: var(--color-muted);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.btn:hover,
.btn:focus {
  text-decoration: none;
}

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

.btn-primary:hover,
.btn-primary:focus {
  background-color: #1a4fb4;
  color: #ffffff;
}

.btn-ghost {
  background-color: var(--color-card);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-ghost:hover,
.btn-ghost:focus {
  background-color: #eef2fa;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
  color: var(--color-muted);
  margin-bottom: 16px;
}

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

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

.breadcrumb-sep {
  color: #b6bfcd;
}

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

/* 页面标题区 */
.page-header {
  margin-bottom: 28px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

.page-description,
.page-lead,
.page-lede {
  margin-top: 10px;
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  max-width: 760px;
}

/* 模块标题 */
.section-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
}

.section-desc,
.section-intro {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

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

/* 页内目录 */
.page-toc {
  align-self: start;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  box-shadow: var(--shadow-card);
}

.toc-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toc-item a {
  display: block;
  padding: 7px 0;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.5;
}

.toc-item a:hover,
.toc-item a:focus {
  color: var(--color-primary);
}

.toc-note {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--color-line);
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* 任务带 */
.task-band {
  max-width: var(--container);
  margin: 32px auto 0;
  padding: 20px 24px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.task-band-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text);
}

.task-band-text,
.task-band-desc {
  margin-top: 6px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.task-band-link {
  display: inline-flex;
  align-items: center;
  margin-top: 12px;
  min-height: 44px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
}

.task-band-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 14px;
}

.task-band-actions .task-band-link {
  margin-top: 0;
  padding: 0 16px;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
}

.task-band-actions .task-band-link:hover,
.task-band-actions .task-band-link:focus {
  background-color: #eef2fa;
  text-decoration: none;
}

/* 页脚 */
.site-footer {
  margin-top: 48px;
  background-color: #ffffff;
  border-top: 1px solid var(--color-line);
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 36px var(--gutter) 24px;
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 28px;
}

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

.footer-brand-desc {
  margin-top: 8px;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

.footer-col-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

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

.footer-list a {
  display: inline-block;
  padding: 3px 0;
  font-size: 13px;
  color: var(--color-muted);
}

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

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

.footer-copy {
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px var(--gutter);
  font-size: 12px;
  color: var(--color-muted);
}

/* 通用图片容器 */
figure {
  overflow: hidden;
}

figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ===================== pages: 首页 ===================== */

/* 首屏任务路径区 */
.hero-task-path {
  padding: 32px 0 8px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 32px;
  align-items: start;
}

.hero-copy {
  padding-top: 8px;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-text);
}

.hero-lead {
  margin-top: 14px;
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.8;
  max-width: 520px;
}

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

.hero-media {
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-line);
  background-color: var(--color-card);
}

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

.hero-caption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
  border-top: 1px solid var(--color-line);
}

.hero-log {
  margin-top: 24px;
  padding: 16px 20px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.hero-log-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.log-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px 20px;
}

.log-item {
  display: flex;
  gap: 10px;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.6;
  padding: 4px 0;
}

.log-date {
  color: var(--color-accent);
  font-weight: 600;
  white-space: nowrap;
}

/* 频道方向总览 */
.channel-overview,
.topic-highlights,
.field-boundary-summary,
.browse-steps,
.site-index {
  margin-top: 44px;
}

.channel-overview .section-desc a,
.topic-highlights .section-desc a,
.field-boundary-summary .section-desc a,
.browse-steps .section-desc a,
.channel-samples .section-desc a,
.channel-advice .section-desc a {
  margin-left: 6px;
  font-weight: 600;
}

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

.channel-row {
  display: grid;
  grid-template-columns: 64px minmax(140px, 0.7fr) minmax(0, 1.4fr) minmax(0, 1.3fr);
  gap: 16px;
  align-items: start;
  padding: 16px 18px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.channel-row:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.channel-code {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-primary);
  background-color: #eef2fa;
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  text-align: center;
  align-self: start;
}

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

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

.channel-samples {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.sample {
  display: inline-block;
  font-size: 12px;
  color: var(--color-text);
  background-color: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  line-height: 1.6;
}

/* 专题策展速览 */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

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

.topic-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.topic-media {
  border-bottom: 1px solid var(--color-line);
}

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

.topic-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text);
  padding: 14px 18px 0;
}

.topic-desc {
  padding: 8px 18px 0;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  flex: 1 1 auto;
}

.topic-count {
  padding: 12px 18px 16px;
  font-size: 12px;
  color: var(--color-accent);
  font-weight: 600;
}

/* 字段与收录边界摘要 */
.summary-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.summary-col {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  box-shadow: var(--shadow-card);
}

.summary-col-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 12px;
}

.field-mini-list {
  display: grid;
  grid-template-columns: minmax(70px, auto) minmax(0, 1fr);
  gap: 8px 14px;
}

.field-mini-term {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text);
}

.field-mini-desc {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

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

.boundary-mini-item {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
  padding-left: 14px;
  position: relative;
}

.boundary-mini-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

/* 浏览顺序四步 */
.step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.step-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.step-item:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.step-index {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: #ffffff;
  background-color: var(--color-primary);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  margin-bottom: 10px;
}

.step-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.step-desc {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

.step-check {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--color-line);
  font-size: 12px;
  color: var(--color-accent);
  line-height: 1.6;
}

/* 站内栏目索引 */
.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}

.index-col {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-card);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.index-col:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

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

.index-desc {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ===================== pages: 内页公共布局 ===================== */

.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  align-items: start;
}

.page-layout .channel-table,
.page-layout .channel-samples,
.page-layout .channel-advice {
  grid-column: 1;
}

.page-layout .channel-figure {
  grid-column: 1;
}

.page-layout .page-toc {
  grid-column: 2;
  grid-row: 1 / span 4;
}

/* 频道分类页 */
.channel-table .section-desc {
  margin-bottom: 16px;
}

.channel-table .channel-list {
  gap: 8px;
}

.channel-table .channel-row {
  grid-template-columns: 64px minmax(0, 1fr);
}

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

.channel-figure {
  margin-top: 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-line);
  background-color: var(--color-card);
}

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

.channel-figure figcaption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
  border-top: 1px solid var(--color-line);
}

.channel-samples,
.channel-advice {
  margin-top: 36px;
}

.sample-group {
  padding: 16px 18px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  margin-bottom: 10px;
}

.sample-channel {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.sample-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.sample-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 10px 12px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

.sample-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.sample-meta {
  font-size: 12px;
  color: var(--color-muted);
}

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

.advice-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-card);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.advice-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

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

.advice-desc {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

.advice-pick {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px dashed var(--color-line);
  font-size: 13px;
  color: var(--color-primary);
  font-weight: 600;
}

/* 专题片单页 */
.topic-layout {
  display: block;
}

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

.topic-cards,
.selection-criteria,
.topic-vs-channel {
  margin-bottom: 36px;
}

.topic-hero {
  margin: 18px 0 22px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-line);
  background-color: var(--color-card);
}

.topic-hero img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.topic-hero-caption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
  border-top: 1px solid var(--color-line);
}

.topic-cards .topic-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.topic-card-media {
  border-bottom: 1px solid var(--color-line);
}

.topic-card-media img {
  width: 100%;
  height: 170px;
  object-fit: cover;
}

.topic-card-body {
  padding: 14px 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1 1 auto;
}

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

.topic-card-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
}

.topic-card-meta {
  font-size: 12px;
  color: var(--color-accent);
  font-weight: 600;
}

.criteria-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 16px;
}

.criteria-item {
  padding: 16px 18px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.criteria-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.criteria-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.vs-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 16px;
}

.vs-column {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  box-shadow: var(--shadow-card);
}

.vs-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.vs-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

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

.vs-list li {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
  padding-left: 14px;
  position: relative;
}

.vs-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-primary);
}

.vs-note {
  margin-top: 16px;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.75;
}

/* 浏览指引页 */
.page-header-text {
  min-width: 0;
}

.page-toc-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.page-toc-list a {
  display: block;
  padding: 7px 0;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.5;
}

.page-toc-list a:hover,
.page-toc-list a:focus {
  color: var(--color-primary);
}

.step-sequence,
.common-obstacles,
.no-result-adjust {
  margin-bottom: 36px;
}

.section-media {
  margin: 18px 0 22px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-line);
  background-color: var(--color-card);
}

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

.section-media figcaption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
  border-top: 1px solid var(--color-line);
}

.step-sequence .step-list {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.step-sequence .step-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 14px;
  align-items: start;
}

.step-sequence .step-index {
  grid-row: 1 / span 3;
  margin-bottom: 0;
  padding: 6px 10px;
  font-size: 13px;
}

.step-sequence .step-name {
  grid-column: 2;
}

.step-sequence .step-desc {
  grid-column: 2;
}

.step-sequence .step-check {
  grid-column: 2;
}

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

.obstacle-item {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  overflow: hidden;
}

.obstacle-summary {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
}

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

.obstacle-summary::after {
  content: "+";
  margin-left: auto;
  font-size: 18px;
  color: var(--color-primary);
}

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

.obstacle-body {
  padding: 0 18px 16px;
  border-top: 1px solid var(--color-line);
}

.obstacle-symptom {
  padding-top: 12px;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.75;
}

.obstacle-fix {
  margin-top: 8px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.adjust-layout {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.adjust-restate,
.adjust-actions {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  box-shadow: var(--shadow-card);
}

.adjust-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.adjust-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.adjust-condition-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.adjust-condition {
  font-size: 13px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 8px 12px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
}

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

.adjust-action {
  counter-increment: adjust;
  position: relative;
  padding-left: 34px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.adjust-action::before {
  content: counter(adjust);
  position: absolute;
  left: 0;
  top: 2px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 12px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 字段与边界页 */
.layout-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  align-items: start;
}

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

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

.field-table-section,
.scope-section,
.archive-section,
.related-section {
  margin-bottom: 36px;
}

.section-figure {
  margin: 18px 0 22px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-line);
  background-color: var(--color-card);
}

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

.figure-caption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--color-muted);
  line-height: 1.6;
  border-top: 1px solid var(--color-line);
}

.field-table {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-card);
  box-shadow: var(--shadow-card);
}

.field-row {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 16px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--color-line);
}

.field-row:last-child {
  border-bottom: none;
}

.field-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text);
}

.field-value {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
}

.scope-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 16px;
}

.scope-col {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  box-shadow: var(--shadow-card);
}

.scope-col-covered {
  border-top: 3px solid var(--color-primary);
}

.scope-col-excluded {
  border-top: 3px solid var(--color-accent);
}

.scope-col-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

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

.scope-list li {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
  padding-left: 14px;
  position: relative;
}

.scope-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-line);
}

.scope-col-covered .scope-list li::before {
  background-color: var(--color-primary);
}

.scope-col-excluded .scope-list li::before {
  background-color: var(--color-accent);
}

.scope-note {
  margin-top: 14px;
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.75;
}

.archive-group {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  box-shadow: var(--shadow-card);
  margin-bottom: 12px;
}

.archive-month {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

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

.archive-item {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr);
  gap: 14px;
  padding: 8px 0;
  border-top: 1px dashed var(--color-line);
}

.archive-date {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

.archive-text {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

.related-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.related-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px;
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.related-item:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.related-item a {
  font-size: 15px;
  font-weight: 600;
}

.related-note {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.7;
}

/* ===================== pages: 404 ===================== */

.error-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gutter) 40px;
}

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

.error-code {
  font-size: 44px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

.error-title {
  margin-top: 8px;
  font-size: 26px;
  font-weight: 700;
  color: var(--color-text);
}

.error-text {
  margin-top: 12px;
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  max-width: 640px;
}

.error-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.error-links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
}

.error-links a:hover,
.error-links a:focus {
  background-color: #eef2fa;
  text-decoration: none;
}

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

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

.error-tip-list li {
  background-color: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 16px 18px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.75;
  box-shadow: var(--shadow-card);
}

/* ===================== 动效增强 ===================== */

@media (prefers-reduced-motion: no-preference) {
  .channel-row,
  .topic-card,
  .step-item,
  .index-col,
  .advice-card,
  .related-item {
    will-change: transform;
  }
}

/* ===================== responsive ===================== */

@media (max-width: 1024px) {
  .footer-inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

  .channel-row {
    grid-template-columns: 56px minmax(120px, 0.8fr) minmax(0, 1.6fr);
  }

  .channel-row .channel-samples {
    grid-column: 2 / -1;
  }
}

@media (max-width: 768px) {
  .header-inner {
    height: 58px;
    position: relative;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: block;
    background-color: var(--color-card);
    border-bottom: 1px solid var(--color-line);
    box-shadow: 0 6px 16px rgba(28, 36, 48, 0.08);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px var(--gutter) 12px;
  }

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

  .nav-item {
    display: block;
  }

  .nav-link {
    display: flex;
    min-height: 48px;
    padding: 12px 4px;
    font-size: 15px;
    border-bottom: 1px solid var(--color-line);
  }

  .nav-link.is-current {
    border-bottom-color: var(--color-line);
    color: var(--color-primary);
  }

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

  .hero-task-path {
    padding-top: 24px;
  }

  .hero-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

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

  .hero-media img {
    height: 220px;
  }

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

  .channel-row {
    grid-template-columns: 52px minmax(0, 1fr);
    gap: 10px 14px;
    padding: 14px;
  }

  .channel-row .channel-scope,
  .channel-row .channel-samples {
    grid-column: 1 / -1;
  }

  .topic-grid,
  .topic-cards .topic-grid,
  .summary-columns,
  .vs-columns,
  .scope-columns,
  .adjust-layout,
  .related-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .step-list,
  .step-sequence .step-list,
  .advice-grid,
  .sample-list,
  .error-tip-list {
    grid-template-columns: minmax(0, 1fr);
  }

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

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

  .page-layout .channel-table,
  .page-layout .channel-figure,
  .page-layout .channel-samples,
  .page-layout .channel-advice,
  .page-layout .page-toc {
    grid-column: 1;
    grid-row: auto;
  }

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

  .field-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

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

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
    padding-top: 28px;
  }

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

  .task-band {
    margin-left: 16px;
    margin-right: 16px;
    padding: 18px;
  }

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

  .error-panel {
    padding: 24px 20px;
  }

  .error-code {
    font-size: 36px;
  }

  .error-title {
    font-size: 22px;
  }
}

@media (max-width: 480px) {
  .index-grid,
  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-actions .btn,
  .task-band-actions .btn,
  .task-band-actions .task-band-link {
    width: 100%;
  }

  .field-mini-list {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px 0;
  }

  .field-mini-desc {
    margin-bottom: 8px;
  }
}