/* ==========================================================================
   base — 全局基础样式
   ========================================================================== */

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: #111827;
  background-color: #F9FAFB;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a {
  color: #2563EB;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #1D4ED8;
}

ul,
ol {
  list-style: none;
}

button {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  color: #1F2937;
  line-height: 1.3;
}

details summary {
  cursor: pointer;
  list-style: none;
}

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

/* ==========================================================================
   layout — 全站布局骨架
   ========================================================================== */

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

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

/* 页头 */
.site-header {
  background-color: #1F2937;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand-logo {
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: 0;
  white-space: nowrap;
}

.brand-logo:hover {
  color: #F59E0B;
}

/* 主导航 */
.site-nav {
  display: flex;
  align-items: center;
}

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

.nav-list a {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: #D1D5DB;
  border-radius: 6px;
  transition: background-color 0.2s ease, color 0.2s ease;
  min-height: 44px;
  line-height: 28px;
}

.nav-list a:hover {
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-list a.is-current {
  color: #F59E0B;
  background-color: rgba(245, 158, 11, 0.12);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border-radius: 6px;
}

.nav-toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: #ffffff;
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

/* 页脚 */
.site-footer {
  background-color: #1F2937;
  color: #9CA3AF;
  margin-top: auto;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px 32px;
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr;
  gap: 40px;
}

.footer-logo {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.7;
  color: #9CA3AF;
}

.footer-title {
  font-size: 15px;
  font-weight: 600;
  color: #F9FAFB;
  margin-bottom: 14px;
}

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

.footer-nav a {
  color: #9CA3AF;
  font-size: 14px;
  transition: color 0.2s ease;
  display: inline-block;
  padding: 4px 0;
}

.footer-nav a:hover {
  color: #F59E0B;
}

.footer-help p:not(.footer-title) {
  font-size: 14px;
  line-height: 1.7;
  color: #9CA3AF;
  margin-bottom: 8px;
}

.footer-help .footer-title + p {
  margin-bottom: 16px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px;
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: #6B7280;
}

/* 内页共用骨架 */
.inner-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px 64px;
  width: 100%;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 20px 0 0;
  font-size: 14px;
  color: #6B7280;
}

.breadcrumb a {
  color: #2563EB;
  transition: color 0.2s ease;
  padding: 4px 0;
}

.breadcrumb a:hover {
  color: #1D4ED8;
}

.breadcrumb-sep {
  color: #9CA3AF;
}

.breadcrumb-current {
  color: #4B5563;
  font-weight: 500;
}

/* 页面标题区 */
.page-header {
  background-color: #F3F4F6;
  border-radius: 8px;
  padding: 32px 40px;
  margin: 16px 0 32px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: #1F2937;
  margin-bottom: 10px;
}

.page-description {
  font-size: 16px;
  line-height: 1.7;
  color: #4B5563;
  max-width: 720px;
}

/* ==========================================================================
   components — 通用组件
   ========================================================================== */

/* 区块标题 */
.section-title {
  font-size: 24px;
  font-weight: 700;
  color: #1F2937;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 15px;
  line-height: 1.7;
  color: #4B5563;
  margin-bottom: 24px;
  max-width: 720px;
}

/* 卡片通用 */
.channel-card,
.collection-card {
  background-color: #ffffff;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.channel-card:hover,
.collection-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

/* 图片容器 */
.channel-media,
.collection-figure,
.hero-media,
.guide-flow-figure,
.feedback-media {
  overflow: hidden;
  background-color: #E5E7EB;
}

.channel-media img,
.collection-figure img,
.collection-image,
.hero-media img,
.guide-flow-figure img,
.feedback-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 折叠问答 */
.faq-item {
  background-color: #ffffff;
  border-radius: 8px;
  border: 1px solid #E5E7EB;
  margin-bottom: 10px;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.faq-item:hover {
  border-color: #D1D5DB;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
}

.faq-item summary {
  padding: 16px 44px 16px 20px;
  font-size: 16px;
  font-weight: 600;
  color: #1F2937;
  position: relative;
  line-height: 1.5;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.faq-item summary::after {
  content: "";
  position: absolute;
  right: 20px;
  top: 50%;
  width: 10px;
  height: 10px;
  border-right: 2px solid #6B7280;
  border-bottom: 2px solid #6B7280;
  transform: translateY(-70%) rotate(45deg);
  transition: transform 0.2s ease;
}

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

.faq-answer {
  padding: 0 20px 18px;
  border-top: 1px solid #F3F4F6;
}

.faq-answer p {
  padding-top: 14px;
  font-size: 15px;
  line-height: 1.7;
  color: #4B5563;
  margin-bottom: 8px;
}

/* 相关链接模块 */
.related-links {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid #E5E7EB;
}

.related-links-label {
  font-size: 14px;
  font-weight: 600;
  color: #6B7280;
  margin-right: 16px;
}

.related-links-item {
  display: inline-block;
  font-size: 14px;
  margin-right: 16px;
  padding: 6px 12px;
  border-radius: 6px;
  background-color: #F3F4F6;
  color: #2563EB;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.related-links-item:hover {
  background-color: #2563EB;
  color: #ffffff;
}

/* ==========================================================================
   pages — 首页
   ========================================================================== */

.home-main {
  width: 100%;
}

/* 首屏工作台 */
.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 56px 20px 40px;
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-copy h1 {
  font-size: 40px;
  font-weight: 700;
  color: #1F2937;
  line-height: 1.25;
  margin-bottom: 16px;
}

.hero-lead {
  font-size: 20px;
  font-weight: 500;
  color: #F59E0B;
  margin-bottom: 12px;
}

.hero-desc {
  font-size: 16px;
  line-height: 1.7;
  color: #4B5563;
  margin-bottom: 28px;
  max-width: 520px;
}

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

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 8px;
  min-height: 44px;
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary {
  background-color: #F59E0B;
  color: #111827;
}

.btn-primary:hover {
  background-color: #D97706;
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
}

.btn-secondary {
  background-color: #ffffff;
  color: #2563EB;
  border: 1px solid #2563EB;
}

.btn-secondary:hover {
  background-color: #2563EB;
  color: #ffffff;
}

.hero-media {
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
  aspect-ratio: 4 / 3;
}

/* 命令面板 */
.command-panel {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.command-item {
  display: flex;
  align-items: center;
  gap: 14px;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 16px 20px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
  min-height: 56px;
}

.command-item:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

.command-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  font-size: 20px;
  flex-shrink: 0;
}

.command-label {
  font-size: 15px;
  font-weight: 600;
  color: #1F2937;
}

/* 首页内容区块通用 */
.channels,
.collections,
.steps,
.faq-teaser {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 20px;
}

.section-head {
  margin-bottom: 28px;
}

.section-head h2 {
  font-size: 26px;
  font-weight: 700;
  color: #1F2937;
  margin-bottom: 8px;
}

.section-head p {
  font-size: 15px;
  line-height: 1.7;
  color: #6B7280;
  max-width: 640px;
}

/* 首页频道网格 */
.channel-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.channel-card {
  padding: 0;
}

.channel-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.channel-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: #1F2937;
  padding: 16px 16px 4px;
}

.channel-card p {
  font-size: 14px;
  line-height: 1.6;
  color: #6B7280;
  padding: 0 16px;
}

.card-link {
  display: inline-block;
  margin: 12px 16px 16px;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  padding: 4px 0;
}

.card-link:hover {
  color: #1D4ED8;
  text-decoration: underline;
}

/* 首页专题网格 */
.collection-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.collection-card {
  display: flex;
  flex-direction: column;
}

.collection-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.collection-info {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.collection-info h3 {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 6px;
}

.series-count {
  font-size: 13px;
  font-weight: 500;
  color: #F59E0B;
  margin-bottom: 8px;
}

.collection-info p:not(.series-count) {
  font-size: 14px;
  line-height: 1.6;
  color: #6B7280;
  margin-bottom: 12px;
  flex-grow: 1;
}

/* 首页步骤 */
.step-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.step-item {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 28px 24px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  position: relative;
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background-color: #F59E0B;
  color: #111827;
  font-size: 18px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 16px;
}

.step-item h3 {
  font-size: 18px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.step-item p {
  font-size: 14px;
  line-height: 1.7;
  color: #6B7280;
}

.section-link {
  display: inline-block;
  margin-top: 24px;
  font-size: 15px;
  font-weight: 500;
  color: #2563EB;
  padding: 8px 0;
}

.section-link:hover {
  color: #1D4ED8;
  text-decoration: underline;
}

/* 首页 FAQ 摘要 */
.faq-teaser .faq-list {
  max-width: 800px;
}

/* ==========================================================================
   pages — 频道导航页
   ========================================================================== */

.channel-map {
  margin-bottom: 48px;
}

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

.channel-media {
  aspect-ratio: 16 / 10;
}

.channel-body {
  padding: 20px;
}

.channel-name {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.channel-desc {
  font-size: 14px;
  line-height: 1.7;
  color: #6B7280;
  margin-bottom: 12px;
}

.channel-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  padding: 4px 0;
}

.channel-link:hover {
  color: #1D4ED8;
  text-decoration: underline;
}

/* 频道使用提示 */
.channel-tips {
  margin-bottom: 48px;
}

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

.tip-item {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.tip-title {
  font-size: 16px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.tip-text {
  font-size: 14px;
  line-height: 1.7;
  color: #6B7280;
}

/* 频道与专题关系 */
.channel-relation {
  margin-bottom: 40px;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 28px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.relation-content p {
  font-size: 15px;
  line-height: 1.8;
  color: #4B5563;
  margin-bottom: 12px;
}

.relation-content p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   pages — 精选专题页
   ========================================================================== */

.collection-list {
  margin-bottom: 48px;
}

.collection-list .collection-grid {
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.collection-figure {
  aspect-ratio: 4 / 3;
}

.collection-body {
  padding: 20px;
}

.collection-name {
  font-size: 20px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 8px;
}

.collection-desc {
  font-size: 14px;
  line-height: 1.7;
  color: #6B7280;
  margin-bottom: 8px;
}

.collection-meta {
  font-size: 13px;
  font-weight: 500;
  color: #F59E0B;
  margin-bottom: 12px;
}

.collection-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  padding: 4px 0;
}

.collection-link:hover {
  color: #1D4ED8;
  text-decoration: underline;
}

/* 专题详情 */
.collection-detail {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 32px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  margin-bottom: 32px;
}

.detail-header {
  border-bottom: 1px solid #F3F4F6;
  padding-bottom: 20px;
  margin-bottom: 24px;
}

.detail-desc {
  font-size: 15px;
  line-height: 1.7;
  color: #6B7280;
}

.detail-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 40px;
}

.detail-subtitle {
  font-size: 18px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 16px;
}

.series-list {
  counter-reset: series-counter;
}

.series-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid #F3F4F6;
}

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

.series-index {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: #F3F4F6;
  color: #4B5563;
  font-size: 14px;
  font-weight: 600;
  border-radius: 6px;
  flex-shrink: 0;
}

.series-info {
  flex: 1;
}

.series-name {
  font-size: 15px;
  font-weight: 500;
  color: #1F2937;
  margin-bottom: 2px;
}

.series-note {
  font-size: 13px;
  color: #6B7280;
}

.info-list {
  margin-bottom: 16px;
}

.info-list dt {
  font-size: 13px;
  font-weight: 600;
  color: #6B7280;
  margin-bottom: 2px;
}

.info-list dd {
  font-size: 15px;
  color: #1F2937;
  margin-bottom: 12px;
}

.aside-tip {
  font-size: 13px;
  line-height: 1.6;
  color: #6B7280;
  background-color: #F9FAFB;
  border-radius: 6px;
  padding: 12px 16px;
  border-left: 3px solid #F59E0B;
}

/* 前后导航 */
.pager {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 40px;
}

.pager-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 16px 20px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
  min-width: 180px;
}

.pager-link:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

.pager-prev {
  align-items: flex-start;
}

.pager-next {
  align-items: flex-end;
  margin-left: auto;
}

.pager-label {
  font-size: 13px;
  color: #6B7280;
}

.pager-title {
  font-size: 16px;
  font-weight: 600;
  color: #1F2937;
}

/* 相关列表 */
.related-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.related-list a {
  display: block;
  background-color: #F3F4F6;
  border-radius: 6px;
  padding: 12px 16px;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.related-list a:hover {
  background-color: #2563EB;
  color: #ffffff;
}

/* ==========================================================================
   pages — 观看指引页
   ========================================================================== */

.guide-summary {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 32px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  margin-bottom: 32px;
}

.guide-flow-figure {
  border-radius: 8px;
  aspect-ratio: 16 / 6;
  margin-top: 20px;
}

.guide-flow-figure figcaption {
  font-size: 13px;
  color: #6B7280;
  text-align: center;
  padding: 10px 0 0;
}

.guide-steps {
  margin-bottom: 40px;
}

.guide-step {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 28px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  margin-bottom: 16px;
  border-left: 4px solid #F59E0B;
}

.guide-step h3 {
  font-size: 18px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 12px;
}

.guide-step p {
  font-size: 15px;
  line-height: 1.7;
  color: #4B5563;
  margin-bottom: 8px;
}

.guide-step p:last-child {
  margin-bottom: 0;
}

.guide-checklist {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 32px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  margin-bottom: 40px;
}

.checklist {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 20px;
}

.checklist li {
  background-color: #F9FAFB;
  border-radius: 8px;
  padding: 20px;
  border: 1px solid #F3F4F6;
}

.checklist h3 {
  font-size: 15px;
  font-weight: 600;
  color: #1F2937;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.checklist h3::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: #2563EB;
  border-radius: 50%;
  flex-shrink: 0;
}

.checklist p {
  font-size: 14px;
  line-height: 1.6;
  color: #6B7280;
}

.related-help {
  margin-top: 24px;
}

.help-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 16px;
}

.help-links a {
  display: inline-block;
  background-color: #F3F4F6;
  border-radius: 6px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.help-links a:hover {
  background-color: #2563EB;
  color: #ffffff;
}

/* ==========================================================================
   pages — 答疑中心页
   ========================================================================== */

.faq-list {
  margin-bottom: 40px;
}

.faq-list .section-title {
  margin-top: 32px;
  padding-bottom: 8px;
  border-bottom: 2px solid #F3F4F6;
}

.faq-list .section-title:first-child {
  margin-top: 0;
}

.faq-group {
  margin-top: 12px;
}

/* 反馈与建议 */
.feedback-note {
  background-color: #ffffff;
  border-radius: 8px;
  padding: 32px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  margin-bottom: 40px;
}

.feedback-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 40px;
  align-items: center;
}

.feedback-text p {
  font-size: 15px;
  line-height: 1.7;
  color: #4B5563;
  margin-bottom: 12px;
}

.feedback-list {
  margin: 16px 0;
  padding-left: 0;
}

.feedback-list li {
  font-size: 14px;
  line-height: 1.7;
  color: #6B7280;
  padding: 6px 0 6px 20px;
  position: relative;
}

.feedback-list li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 14px;
  width: 6px;
  height: 6px;
  background-color: #F59E0B;
  border-radius: 50%;
}

.feedback-media {
  border-radius: 8px;
  aspect-ratio: 4 / 3;
}

/* ==========================================================================
   pages — 404 页
   ========================================================================== */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 20px;
  flex: 1;
}

.error-panel {
  text-align: center;
  max-width: 560px;
  width: 100%;
  background-color: #ffffff;
  border-radius: 8px;
  padding: 48px 40px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: #F59E0B;
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 28px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  line-height: 1.7;
  color: #6B7280;
  margin-bottom: 24px;
}

.error-btn {
  display: inline-block;
  background-color: #F59E0B;
  color: #111827;
  font-size: 16px;
  font-weight: 600;
  padding: 12px 32px;
  border-radius: 8px;
  min-height: 44px;
  transition: background-color 0.2s ease, color 0.2s ease;
  margin-bottom: 32px;
}

.error-btn:hover {
  background-color: #D97706;
  color: #ffffff;
}

.error-links p {
  font-size: 14px;
  color: #6B7280;
  margin-bottom: 12px;
}

.error-links ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.error-links a {
  display: inline-block;
  background-color: #F3F4F6;
  border-radius: 6px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: #2563EB;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.error-links a:hover {
  background-color: #2563EB;
  color: #ffffff;
}

/* ==========================================================================
   responsive — 响应式断点
   ========================================================================== */

/* 平板 */
@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero-media {
    max-width: 560px;
  }

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

  .channel-map .channel-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .detail-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .detail-aside {
    border-top: 1px solid #F3F4F6;
    padding-top: 24px;
  }

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

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

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

/* 手机 */
@media (max-width: 768px) {
  .header-inner {
    height: 56px;
    padding: 0 16px;
  }

  .brand-logo {
    font-size: 18px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background-color: #1F2937;
    flex-direction: column;
    align-items: stretch;
    padding: 8px 16px 16px;
    gap: 4px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  }

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

  .nav-list a {
    padding: 12px 16px;
    border-radius: 6px;
  }

  .hero {
    padding: 40px 16px 32px;
  }

  .hero-copy h1 {
    font-size: 30px;
  }

  .hero-lead {
    font-size: 17px;
  }

  .hero-actions {
    flex-direction: column;
    gap: 12px;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
  }

  .command-panel {
    grid-template-columns: repeat(2, 1fr);
    padding: 0 16px 16px;
  }

  .channels,
  .collections,
  .steps,
  .faq-teaser {
    padding: 40px 16px;
  }

  .channel-grid,
  .channel-map .channel-grid,
  .collection-grid,
  .collection-list .collection-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .step-list {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .tips-list {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .checklist {
    grid-template-columns: 1fr;
  }

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

  .pager {
    flex-direction: column;
    gap: 12px;
  }

  .pager-link {
    width: 100%;
  }

  .pager-next {
    margin-left: 0;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 32px 16px 24px;
  }

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

  .inner-main {
    padding: 0 16px 48px;
  }

  .page-header {
    padding: 24px 20px;
    margin: 12px 0 24px;
  }

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

  .breadcrumb {
    padding-top: 16px;
    font-size: 13px;
  }

  .collection-detail {
    padding: 20px;
  }

  .guide-summary,
  .guide-checklist,
  .feedback-note {
    padding: 24px 20px;
  }

  .guide-step {
    padding: 24px 20px;
  }

  .error-panel {
    padding: 32px 24px;
  }

  .error-code {
    font-size: 56px;
  }
}

/* 小屏手机 */
@media (max-width: 390px) {
  .command-panel {
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    font-size: 26px;
  }

  .related-list {
    grid-template-columns: 1fr;
  }

  .checklist {
    grid-template-columns: 1fr;
  }

  .help-links {
    flex-direction: column;
  }

  .help-links a {
    text-align: center;
  }
}