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

:root {
  --bg-dark: #0f1115;
  --bg-card: #2a2f3a;
  --bg-card-hover: #333946;
  --text-light: #f5f2ea;
  --text-muted: #b8b3a8;
  --accent: #ff5c38;
  --accent-hover: #ff7a5c;
  --border-subtle: rgba(245, 242, 234, 0.12);
  --radius: 8px;
  --container: 1200px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --transition: 0.2s ease;
}

*,
*::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: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-light);
  background-color: var(--bg-dark);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

a:hover {
  color: var(--accent-hover);
}

ul,
ol {
  list-style: none;
}

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

strong {
  font-weight: 600;
}

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

/* ============================================================
   LAYOUT — 全站骨架
   ============================================================ */

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

.site-header {
  background: rgba(15, 17, 21, 0.95);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 24px;
}

.brand-logo {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-light);
  letter-spacing: 0.02em;
  white-space: nowrap;
  flex-shrink: 0;
}

.brand-logo:hover {
  color: var(--accent);
}

.site-nav {
  display: flex;
  align-items: center;
  flex: 1;
  justify-content: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-list li a {
  display: inline-block;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--text-muted);
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
}

.nav-list li a:hover {
  color: var(--text-light);
  background: rgba(245, 242, 234, 0.06);
}

.nav-list li a.is-current {
  color: var(--accent);
  background: rgba(255, 92, 56, 0.1);
}

.nav-feedback {
  display: inline-block;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-light);
  background: var(--accent);
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background var(--transition);
  flex-shrink: 0;
}

.nav-feedback:hover {
  background: var(--accent-hover);
  color: var(--text-light);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}

.toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-light);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

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

/* ============================================================
   LAYOUT — 页脚
   ============================================================ */

.site-footer {
  background: #0c0e12;
  border-top: 1px solid var(--border-subtle);
  margin-top: 0;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px 24px 40px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.footer-col h2 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 16px;
}

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

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

.footer-col ul li a:hover {
  color: var(--accent);
}

.footer-bottom {
  max-width: var(--container);
  margin: 0 auto;
  padding: 20px 24px 28px;
  border-top: 1px solid rgba(245, 242, 234, 0.06);
  text-align: center;
}

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

/* ============================================================
   COMPONENTS — 按钮
   ============================================================ */

.btn {
  display: inline-block;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  min-height: 44px;
  min-width: 44px;
}

.btn-primary {
  background: var(--accent);
  color: var(--text-light);
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: var(--text-light);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(255, 92, 56, 0.25);
}

.btn-secondary {
  background: transparent;
  color: var(--text-light);
  border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(255, 92, 56, 0.06);
}

/* ============================================================
   COMPONENTS — 通用区块标题
   ============================================================ */

.section-heading {
  max-width: var(--container);
  margin: 0 auto 40px;
  padding: 0 24px;
}

.section-heading h2,
.section-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
  line-height: 1.4;
}

.section-heading p,
.section-desc {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 640px;
}

/* ============================================================
   COMPONENTS — 频道卡片
   ============================================================ */

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

.channel-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.channel-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.channel-card img {
  width: 100%;
  height: 160px;
  border-radius: var(--radius);
  object-fit: cover;
}

.channel-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-light);
}

.channel-tags {
  font-size: 13px;
  color: var(--accent);
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.channel-tags::before {
  content: "";
}

.channel-card p:not(.channel-tags) {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
}

.channel-card a {
  font-size: 14px;
  font-weight: 500;
  margin-top: auto;
  align-self: flex-start;
}

/* ============================================================
   COMPONENTS — 图文交替块
   ============================================================ */

.topic-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  max-width: var(--container);
  margin: 0 auto 56px;
  padding: 0 24px;
}

.topic-figure img,
.topic-media img {
  width: 100%;
  height: 280px;
  border-radius: var(--radius);
  object-fit: cover;
}

.topic-copy h3,
.topic-content h3 {
  font-size: 22px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 12px;
}

.topic-copy p,
.topic-content p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 12px;
  line-height: 1.8;
}

.topic-copy a,
.topic-content a {
  font-size: 14px;
  font-weight: 500;
}

/* ============================================================
   COMPONENTS — 步骤卡片
   ============================================================ */

.steps-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.step-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.step-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.step-number {
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 8px;
}

.step-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

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

/* ============================================================
   COMPONENTS — 更新列表
   ============================================================ */

.update-list {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.update-list li {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.update-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 4px;
  background: rgba(255, 92, 56, 0.15);
  color: var(--accent);
  white-space: nowrap;
  flex-shrink: 0;
}

.update-desc {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
}

/* ============================================================
   COMPONENTS — 反馈卡片
   ============================================================ */

.feedback-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.feedback-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.feedback-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.feedback-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

.feedback-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.7;
}

.feedback-card a {
  font-size: 14px;
  font-weight: 500;
}

/* ============================================================
   COMPONENTS — 模块链接
   ============================================================ */

.module-link {
  text-align: center;
  margin-top: 32px;
}

.module-link a {
  font-size: 15px;
  font-weight: 500;
  padding: 12px 24px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  display: inline-block;
  transition: border-color var(--transition), color var(--transition);
}

.module-link a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ============================================================
   COMPONENTS — FAQ 手风琴
   ============================================================ */

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 500;
  color: var(--text-light);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  min-height: 48px;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--accent);
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item[open] summary {
  border-bottom: 1px solid var(--border-subtle);
}

.faq-content,
.faq-item p {
  padding: 16px 20px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.8;
  background: rgba(15, 17, 21, 0.4);
}

/* ============================================================
   COMPONENTS — 面包屑
   ============================================================ */

.breadcrumb {
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px 24px 0;
  font-size: 14px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

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

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

.breadcrumb-sep {
  color: rgba(245, 242, 234, 0.3);
}

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

/* ============================================================
   PAGES — 首页
   ============================================================ */

/* Hero 首屏焦点区 */
.hero-section {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  max-width: var(--container);
  margin: 0 auto;
  padding: 80px 24px 64px;
}

.hero-content h1 {
  font-size: 40px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-light);
  margin-bottom: 16px;
}

.hero-lead {
  font-size: 17px;
  color: var(--text-muted);
  margin-bottom: 32px;
  max-width: 520px;
  line-height: 1.8;
}

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

.hero-figure img {
  width: 100%;
  height: 360px;
  border-radius: var(--radius);
  object-fit: cover;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
}

/* 品牌与定位承接 */
.brand-story {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px;
  border-top: 1px solid var(--border-subtle);
}

.story-copy h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
}

.story-copy p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 12px;
  line-height: 1.8;
}

.story-figure img {
  width: 100%;
  height: 260px;
  border-radius: var(--radius);
  object-fit: cover;
}

/* 频道分类导览 */
.channel-guide {
  padding: 64px 0;
  background: rgba(42, 47, 58, 0.3);
}

.channel-guide .section-heading,
.channel-guide .channel-grid {
  max-width: var(--container);
  margin-left: auto;
  margin-right: auto;
}

.channel-guide .channel-grid {
  padding: 0 24px;
}

/* 题材专题预览 */
.topic-preview {
  padding: 64px 0;
}

/* 观看指南预告 */
.guide-preview {
  padding: 64px 0;
  background: rgba(42, 47, 58, 0.3);
}

.guide-preview .section-heading {
  margin-bottom: 32px;
}

/* 更新说明摘要 */
.update-summary {
  padding: 64px 0;
}

/* 问题反馈入口 */
.feedback-entry {
  padding: 64px 0;
  background: rgba(42, 47, 58, 0.3);
}

/* ============================================================
   PAGES — 内页通用
   ============================================================ */

.inner-main {
  width: 100%;
  padding-bottom: 80px;
}

.page-header {
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px 24px 32px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 48px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-light);
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--text-muted);
  max-width: 720px;
  line-height: 1.8;
}

/* ============================================================
   PAGES — 频道一览
   ============================================================ */

.channel-filter {
  max-width: var(--container);
  margin: 0 auto 48px;
  padding: 0 24px;
}

.filter-box {
  display: flex;
  gap: 12px;
  align-items: center;
  margin-top: 20px;
  max-width: 480px;
}

.filter-input {
  flex: 1;
  padding: 12px 16px;
  font-size: 15px;
  color: var(--text-light);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  outline: none;
  transition: border-color var(--transition);
  min-height: 44px;
}

.filter-input:focus {
  border-color: var(--accent);
}

.filter-input::placeholder {
  color: rgba(245, 242, 234, 0.4);
}

.filter-clear {
  padding: 10px 16px;
  font-size: 14px;
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  transition: border-color var(--transition), color var(--transition);
  min-height: 44px;
}

.filter-clear:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.filter-status {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 12px;
}

.filter-empty {
  font-size: 15px;
  color: var(--text-muted);
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  max-width: var(--container);
  margin: 0 auto 48px;
}

.channel-grid-section {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.channel-grid-section .section-title {
  margin-bottom: 24px;
}

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

.channel-scene {
  font-size: 13px;
  color: var(--text-muted);
  padding: 8px 12px;
  background: rgba(245, 242, 234, 0.05);
  border-radius: 4px;
  line-height: 1.6;
}

.scene-recommendation {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.scene-recommendation .section-title {
  margin-bottom: 8px;
}

.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
}

.scene-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.scene-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.scene-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

.scene-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.7;
}

.scene-card a {
  font-size: 14px;
  font-weight: 500;
}

/* ============================================================
   PAGES — 题材专题
   ============================================================ */

.topic-list {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.topic-list > h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 40px;
}

.topic-list .topic-block {
  padding: 0;
  margin-bottom: 56px;
}

.topic-content ul.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.topic-tags li {
  font-size: 13px;
  color: var(--accent);
  background: rgba(255, 92, 56, 0.1);
  padding: 4px 12px;
  border-radius: 4px;
}

.topic-channels,
.topic-direction {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
}

.topic-channels strong,
.topic-direction strong {
  color: var(--text-light);
  margin-right: 4px;
}

.topic-channels a {
  margin-right: 8px;
  display: inline-block;
}

.topic-relation {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.topic-relation > h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 32px;
}

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

.relation-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.relation-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.relation-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

.relation-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 12px;
}

.relation-link a {
  font-size: 14px;
  font-weight: 500;
}

.topic-note {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.topic-note h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 16px;
}

.topic-note p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 12px;
  max-width: 720px;
}

/* ============================================================
   PAGES — 观看指南
   ============================================================ */

.page-layout {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.guide-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 48px;
  align-items: start;
}

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

.guide-layout .breadcrumb {
  padding: 24px 0 0;
}

.guide-layout .page-header {
  padding: 32px 0 32px;
  margin-bottom: 40px;
}

.verify-steps {
  margin-bottom: 64px;
}

.verify-steps h2,
.common-issues h2,
.condition-cards h2,
.related-links h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 8px;
}

.verify-steps .section-desc,
.common-issues .section-desc {
  margin-bottom: 32px;
}

.steps-list {
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 32px;
}

.step-item {
  display: flex;
  gap: 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
  align-items: flex-start;
}

.step-item .step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: rgba(255, 92, 56, 0.15);
  color: var(--accent);
  font-weight: 700;
  font-size: 15px;
  border-radius: 50%;
  flex-shrink: 0;
  margin: 0;
}

.step-content {
  flex: 1;
}

.step-content h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 6px;
}

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

.step-visual {
  margin-top: 32px;
}

.guide-figure img {
  width: 100%;
  height: 240px;
  border-radius: var(--radius);
  object-fit: cover;
}

.guide-figure figcaption {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
  text-align: center;
}

.common-issues {
  margin-bottom: 64px;
}

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

.guide-sidebar {
  position: sticky;
  top: 96px;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.condition-cards h2,
.related-links h2 {
  font-size: 18px;
  margin-bottom: 16px;
}

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

.condition-item {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
}

.condition-item h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 6px;
}

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

.related-links ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.related-links ul li a {
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  color: var(--text-muted);
  background: var(--bg-card);
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
  min-height: 44px;
  display: flex;
  align-items: center;
}

.related-links ul li a:hover {
  color: var(--accent);
  background: var(--bg-card-hover);
}

/* ============================================================
   PAGES — 更新说明
   ============================================================ */

.update-timeline {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.update-timeline > h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 32px;
}

.update-timeline .update-list {
  padding: 0;
}

.update-entry {
  display: flex;
  gap: 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
  align-items: flex-start;
}

.update-entry .update-tag {
  margin-top: 4px;
}

.entry-content {
  flex: 1;
}

.entry-content h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 6px;
  line-height: 1.5;
}

.entry-content p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 8px;
}

.entry-meta {
  font-size: 13px;
  color: rgba(245, 242, 234, 0.4);
}

.tag-revision {
  background: rgba(255, 92, 56, 0.15);
  color: var(--accent);
}

.tag-addition {
  background: rgba(80, 200, 120, 0.15);
  color: #50c878;
}

.tag-removal {
  background: rgba(200, 120, 80, 0.15);
  color: #c87850;
}

.update-types {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.update-types > h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 32px;
}

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

.type-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.type-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.type-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

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

.change-scope {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.change-scope > h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  margin-bottom: 24px;
}

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

.scope-list p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  padding: 16px 20px;
  background: var(--bg-card);
  border-radius: var(--radius);
}

.scope-list strong {
  color: var(--text-light);
  margin-right: 8px;
}

.related-links {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  text-align: center;
}

.update-figure {
  margin-bottom: 24px;
}

.update-figure img {
  width: 100%;
  max-width: 720px;
  height: 240px;
  border-radius: var(--radius);
  object-fit: cover;
  margin: 0 auto;
}

.update-figure figcaption {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
}

.related-links p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 16px;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links p a {
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  display: inline-block;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.related-links p a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ============================================================
   PAGES — 问题反馈
   ============================================================ */

.feedback-methods {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.feedback-methods .section-heading {
  padding: 0;
  margin-bottom: 32px;
}

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

.method-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.method-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.method-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

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

.method-card a {
  font-size: 14px;
  font-weight: 500;
  display: inline-block;
  margin-top: 8px;
}

.faq-section {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.faq-section .section-heading {
  padding: 0;
  margin-bottom: 32px;
}

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

.feedback-boundary {
  max-width: var(--container);
  margin: 0 auto 64px;
  padding: 0 24px;
}

.feedback-boundary .section-heading {
  padding: 0;
  margin-bottom: 32px;
}

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

.boundary-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
}

.boundary-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.boundary-card h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 8px;
}

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

.feedback-figure {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.feedback-figure img {
  width: 100%;
  max-width: 720px;
  height: 240px;
  border-radius: var(--radius);
  object-fit: cover;
  margin: 0 auto;
}

.feedback-figure figcaption {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
  text-align: center;
}

/* ============================================================
   PAGES — 404
   ============================================================ */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px;
  flex: 1;
}

.error-section {
  text-align: center;
  max-width: 640px;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-section h1 {
  font-size: 24px;
  font-weight: 600;
  color: var(--text-light);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 32px;
  line-height: 1.8;
}

.error-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.error-help {
  font-size: 14px;
  color: var(--text-muted);
}

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

/* 平板 1024px */
@media (max-width: 1024px) {
  .channel-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .guide-layout {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 32px;
  }

  .hero-section {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 56px 24px 48px;
  }

  .hero-figure img {
    height: 300px;
  }

  .brand-story {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 48px 24px;
  }

  .topic-block {
    grid-template-columns: 1fr;
    gap: 24px;
    margin-bottom: 48px;
  }

  .topic-block-right .topic-copy {
    order: 1;
  }

  .topic-block-right .topic-figure {
    order: 2;
  }

  .relation-grid,
  .type-cards,
  .boundary-list {
    grid-template-columns: repeat(2, 1fr);
  }

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

/* 手机 768px */
@media (max-width: 768px) {
  .header-inner {
    min-height: 64px;
    padding: 0 16px;
  }

  .nav-toggle {
    display: flex;
    order: 3;
  }

  .site-nav {
    order: 2;
    margin-left: auto;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border-subtle);
    padding: 16px;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    z-index: 99;
  }

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

  .nav-list li a {
    display: block;
    padding: 14px 16px;
    font-size: 16px;
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .nav-feedback {
    display: none;
  }

  .nav-list .nav-feedback {
    display: flex;
    margin-top: 8px;
    justify-content: center;
  }

  .hero-content h1 {
    font-size: 32px;
  }

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

  .steps-row,
  .scene-grid,
  .feedback-cards {
    grid-template-columns: 1fr;
  }

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

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px 24px 32px;
  }

  .guide-layout {
    grid-template-columns: 1fr;
  }

  .guide-sidebar {
    position: static;
    order: 2;
  }

  .main-content {
    order: 1;
  }

  .page-title {
    font-size: 28px;
  }

  .page-header {
    padding: 32px 16px 24px;
    margin-bottom: 40px;
  }

  .breadcrumb {
    padding: 20px 16px 0;
  }

  .page-layout,
  .channel-filter,
  .channel-grid-section,
  .scene-recommendation,
  .topic-list,
  .topic-relation,
  .topic-note,
  .update-timeline,
  .update-types,
  .change-scope,
  .related-links,
  .feedback-methods,
  .faq-section,
  .feedback-boundary,
  .feedback-figure {
    padding-left: 16px;
    padding-right: 16px;
  }

  .section-heading {
    padding: 0 16px;
  }

  .topic-block {
    padding: 0 16px;
  }

  .update-list {
    padding: 0 16px;
  }

  .relation-grid,
  .type-cards,
  .boundary-list {
    grid-template-columns: 1fr;
  }

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

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

/* 小屏手机 480px */
@media (max-width: 480px) {
  .hero-content h1 {
    font-size: 28px;
  }

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

  .hero-actions .btn {
    text-align: center;
  }

  .btn {
    padding: 12px 20px;
  }

  .topic-figure img,
  .topic-media img,
  .story-figure img {
    height: 200px;
  }

  .channel-card img {
    height: 140px;
  }

  .update-list li {
    flex-direction: column;
    gap: 8px;
  }

  .step-item {
    flex-direction: column;
  }

  .step-item .step-number {
    width: 32px;
    height: 32px;
    font-size: 14px;
  }

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

  .error-actions .btn {
    text-align: center;
  }
}