/* ==========================================================================
   91传媒 · 整站样式表
   视觉方向：极简品牌风 · 大量留白 · 细分割线 · 单强动作色
   ========================================================================== */

/* ==========================================================================
   Base —— 重置、变量、全局基础
   ========================================================================== */

:root {
  --color-ink: #111111;
  --color-bg: #f5f5f3;
  --color-surface: #ffffff;
  --color-accent: #e85d2a;
  --color-muted: #6b6b6b;
  --color-line: #d9d9d6;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  --container-width: 1200px;
  --container-pad: 24px;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;

  --shadow-card: 0 1px 3px rgba(17, 17, 17, 0.06);
  --shadow-card-hover: 0 8px 24px rgba(17, 17, 17, 0.08);

  --header-h: 72px;
}

*,
*::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: 1.75;
  color: var(--color-ink);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-ink);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  line-height: 1.35;
}

p {
  margin: 0;
}

figure {
  margin: 0;
}

.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：页头、主容器、页脚
   ========================================================================== */

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

.site-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.brand-name {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: 0.02em;
}

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

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

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

.nav-list li a {
  display: block;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--color-muted);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.nav-list li a:hover {
  color: var(--color-accent);
  background-color: rgba(232, 93, 42, 0.06);
}

.nav-list li a.is-current {
  color: var(--color-accent);
  font-weight: 600;
  background-color: rgba(232, 93, 42, 0.08);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  align-items: center;
}

.nav-toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-ink);
  border-radius: 1px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* 主内容区 */
.site-main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.home-main {
  width: 100%;
}

.inner-main {
  max-width: var(--container-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--container-pad) 80px;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 24px 0 0;
  font-size: 14px;
  color: var(--color-muted);
}

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

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

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

.breadcrumb-current {
  color: var(--color-ink);
  font-weight: 500;
}

/* 页面标题区 */
.page-header {
  padding: 28px 0 40px;
  border-bottom: 1px solid var(--color-line);
  margin-bottom: 48px;
}

.page-title {
  font-size: 32px;
  font-weight: 600;
  color: var(--color-ink);
  line-height: 1.3;
}

.page-description {
  margin-top: 12px;
  font-size: 16px;
  color: var(--color-muted);
  max-width: 720px;
}

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

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px var(--container-pad) 32px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 48px;
}

.footer-brand-name {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-ink);
}

.footer-brand-desc {
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  max-width: 320px;
}

.footer-nav-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 16px;
}

.footer-nav ul li {
  margin-bottom: 10px;
}

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

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

.footer-notes p:not(.footer-nav-title) {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 8px;
}

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

.footer-bottom p {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 20px var(--container-pad);
  font-size: 13px;
  color: var(--color-muted);
}

/* ==========================================================================
   Components —— 通用组件：section-heading、链接、FAQ、步骤、卡片等
   ========================================================================== */

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

.section-heading h2,
.section-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-ink);
  line-height: 1.4;
}

.section-heading p,
.section-desc {
  margin-top: 8px;
  font-size: 15px;
  color: var(--color-muted);
  max-width: 640px;
}

.text-link {
  display: inline-block;
  margin-top: 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-accent);
}

.text-link:hover {
  color: var(--color-ink);
}

/* 按钮 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-accent);
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.2s ease;
  min-height: 44px;
}

.btn-primary:hover {
  background-color: #c94e1f;
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background-color: transparent;
  color: var(--color-ink);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-line);
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
  min-height: 44px;
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* FAQ 原生折叠 */
.faq-item {
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 500;
  color: var(--color-ink);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  position: relative;
}

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  font-weight: 400;
  color: var(--color-muted);
  flex-shrink: 0;
  transition: transform 0.2s ease;
}

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

.faq-item summary:hover {
  color: var(--color-accent);
}

.faq-answer {
  padding: 0 24px 20px;
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
}

.faq-answer p + p {
  margin-top: 10px;
}

/* ==========================================================================
   Components —— 卡片通用
   ========================================================================== */

.channel-card,
.featured-main-card,
.featured-sub-card,
.playlist-card,
.help-card,
.feedback-card,
.step-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.channel-card:hover,
.featured-main-card:hover,
.featured-sub-card:hover,
.playlist-card:hover,
.help-card:hover,
.feedback-card:hover,
.step-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

/* ==========================================================================
   Components —— 滚动出现动画（不影响初始可见性）
   ========================================================================== */

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   Pages —— 首页 index.html
   ========================================================================== */

/* Hero 首屏：左右不对称 */
.hero {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 64px var(--container-pad) 72px;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 48px;
  align-items: start;
}

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

.side-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.side-links li {
  margin-bottom: 4px;
}

.side-links li a {
  display: block;
  padding: 8px 12px;
  font-size: 15px;
  color: var(--color-muted);
  border-left: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.side-links li a:hover {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

.hero-content {
  max-width: 640px;
}

.hero-content h1 {
  font-size: 40px;
  font-weight: 600;
  color: var(--color-ink);
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 17px;
  color: var(--color-muted);
  line-height: 1.8;
  margin-bottom: 24px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 32px;
}

.tag {
  display: inline-block;
  padding: 6px 14px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: 100px;
}

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

.hero-media {
  grid-column: 1 / -1;
  margin-top: 48px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  aspect-ratio: 16 / 7;
  box-shadow: var(--shadow-card);
}

.hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 55%,
    rgba(0, 0, 0, 0.18) 100%
  );
  pointer-events: none;
}

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

/* 频道分类速览 */
.channel-overview {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad);
  border-top: 1px solid var(--color-line);
}

.channel-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

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

.channel-card figure {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  position: relative;
}

.channel-card figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.channel-card figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.channel-card:hover figure img {
  transform: scale(1.03);
}

.channel-card h3 {
  padding: 16px 18px 4px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
}

.channel-card p {
  padding: 0 18px 18px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  flex: 1;
}

/* 焦点专题区 */
.featured-playlist {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad);
  border-top: 1px solid var(--color-line);
}

.featured-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 20px;
}

.featured-main-card {
  display: flex;
  flex-direction: column;
}

.featured-main-card figure {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  position: relative;
}

.featured-main-card figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.featured-main-card figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.featured-main-card:hover figure img {
  transform: scale(1.03);
}

.featured-card-body {
  padding: 20px 22px 22px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.featured-card-body h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.featured-card-body p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  flex: 1;
}

.card-link {
  display: inline-block;
  margin-top: 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

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

.featured-sub-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.featured-sub-card {
  display: flex;
  flex: 1;
}

.featured-sub-card figure {
  width: 42%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  position: relative;
  flex-shrink: 0;
}

.featured-sub-card figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.featured-sub-card figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.featured-sub-card .featured-card-body {
  padding: 14px 18px;
}

.featured-sub-card .featured-card-body h3 {
  font-size: 16px;
}

/* 浏览路径提示带 */
.path-strip {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad);
  border-top: 1px solid var(--color-line);
}

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

.path-step {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.path-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.step-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
}

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

.path-step p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 12px;
}

.path-step a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.path-step a:hover {
  color: var(--color-ink);
}

/* 近期维护记录摘要 */
.recent-records {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad);
  border-top: 1px solid var(--color-line);
}

.record-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.record-list li {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  padding: 20px 24px;
}

.record-list li h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 6px;
}

.record-list li p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
}

/* 常见问题摘要 */
.faq-summary {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad);
  border-top: 1px solid var(--color-line);
}

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

.faq-preview-list .faq-item p {
  padding: 0 24px 18px;
  font-size: 14px;
  color: var(--color-muted);
}

/* 帮助入口条 */
.help-band {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 72px var(--container-pad) 88px;
  border-top: 1px solid var(--color-line);
}

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

.help-card {
  display: flex;
  flex-direction: column;
  padding: 28px;
}

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

.help-card p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  flex: 1;
  margin-bottom: 12px;
}

/* ==========================================================================
   Pages —— 频道索引 91cm/pindao.html
   ========================================================================== */

.layout-shell {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 48px;
  align-items: start;
}

.sidebar-left {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 48px;
  align-items: start;
}

.anchor-nav {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  padding: 24px 0;
  border-right: 1px solid var(--color-line);
}

.anchor-nav-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.anchor-nav ul li {
  margin-bottom: 4px;
}

.anchor-nav ul li a {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--color-muted);
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.anchor-nav ul li a:hover {
  color: var(--color-accent);
  background-color: rgba(232, 93, 42, 0.06);
}

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

.channel-group {
  margin-bottom: 56px;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.channel-group h2 {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.group-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
  max-width: 640px;
}

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

.channel-cards .channel-card {
  display: flex;
  flex-direction: column;
}

.card-media {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  position: relative;
}

.card-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.channel-card:hover .card-media img {
  transform: scale(1.03);
}

.channel-card h3 {
  padding: 16px 18px 4px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
}

.channel-audience {
  padding: 0 18px 6px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  flex: 1;
}

.channel-card a {
  display: inline-block;
  margin: 0 18px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.channel-card a:hover {
  color: var(--color-ink);
}

.channel-tips {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.channel-tips h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 12px;
}

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

.channel-tips p:last-child {
  margin-bottom: 0;
}

/* 相关链接 */
.related-links {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--color-line);
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.related-links-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-ink);
}

.related-links-item {
  font-size: 14px;
  color: var(--color-accent);
}

.related-links-item:hover {
  color: var(--color-ink);
}

/* ==========================================================================
   Pages —— 专题片单 91cm/zhuanti.html
   ========================================================================== */

.featured {
  margin-bottom: 64px;
}

.featured-card {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.featured-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.featured-media {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  position: relative;
}

.featured-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.featured-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.featured-card:hover .featured-media img {
  transform: scale(1.03);
}

.featured-body {
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.featured-body h3 {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 12px;
}

.featured-body > p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 16px;
}

.playlist-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.playlist-meta li {
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: 100px;
  padding: 4px 14px;
}

.playlist-meta li span {
  color: var(--color-ink);
  font-weight: 500;
}

/* 专题片单网格 */
.playlist-grid {
  margin-bottom: 64px;
}

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

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

.playlist-cover {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  position: relative;
}

.playlist-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.playlist-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.playlist-card:hover .playlist-cover img {
  transform: scale(1.03);
}

.playlist-info {
  padding: 20px 22px 22px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.playlist-info h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.playlist-info > p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 12px;
  flex: 1;
}

.playlist-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 12px;
}

.playlist-tags li {
  font-size: 12px;
  color: var(--color-muted);
  background-color: var(--color-bg);
  border-radius: 100px;
  padding: 3px 10px;
}

.playlist-audience {
  font-size: 13px;
  color: var(--color-muted);
  padding-top: 12px;
  border-top: 1px solid var(--color-line);
}

/* 专题适用人群 */
.audience-note {
  margin-bottom: 64px;
}

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

.audience-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.audience-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.audience-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 10px;
}

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

/* 相关页面入口 */
.related-inner {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
}

.related-inner p {
  font-size: 14px;
  color: var(--color-muted);
  flex: 1;
  min-width: 200px;
}

.related-inner a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.related-inner a:hover {
  color: var(--color-ink);
}

/* ==========================================================================
   Pages —— 内容进展 91cm/gengxin.html
   ========================================================================== */

.maintenance-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 64px;
}

.intro-copy {
  min-width: 0;
}

.intro-copy .section-title {
  margin-bottom: 16px;
}

.intro-copy p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 12px;
}

.intro-copy p:last-child {
  margin-bottom: 0;
}

.intro-figure {
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  aspect-ratio: 16 / 9;
  box-shadow: var(--shadow-card);
}

.intro-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

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

.intro-figure figcaption {
  position: absolute;
  bottom: 12px;
  left: 16px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.92);
  z-index: 1;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
}

/* 维护记录列表 */
.record-list .section-title,
.principle-list .section-title,
.current-status .section-title {
  margin-bottom: 8px;
}

.record-list .section-desc,
.principle-list .section-desc {
  margin-bottom: 28px;
}

.record-items {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 64px;
}

.record-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.record-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card-hover);
}

.record-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

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

/* 内容调整原则 */
.principle-items {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 64px;
}

.principle-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.principle-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.principle-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 10px;
}

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

/* 当前内容状态 */
.current-status {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.current-status .section-title {
  margin-bottom: 12px;
}

.current-status p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 10px;
}

.current-status p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   Pages —— 观看指南 91cm/zhinan.html
   ========================================================================== */

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

.steps-section .section-title {
  margin-bottom: 28px;
}

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

.step-card {
  padding: 28px;
  display: flex;
  flex-direction: column;
}

.step-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 14px;
}

.step-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 10px;
}

.step-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  flex: 1;
  margin-bottom: 12px;
}

.step-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.step-link:hover {
  color: var(--color-ink);
}

/* 核验说明 */
.verification-section {
  margin-bottom: 64px;
}

.verification-section .section-title {
  margin-bottom: 28px;
}

.verification-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.verification-content p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 12px;
}

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

.verification-figure {
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 16 / 9;
  position: relative;
}

.verification-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

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

.verification-figure figcaption {
  position: absolute;
  bottom: 12px;
  left: 16px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.92);
  z-index: 1;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
}

/* 反馈入口 */
.feedback-section {
  margin-bottom: 16px;
}

.feedback-section .section-title {
  margin-bottom: 28px;
}

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

.feedback-card {
  padding: 28px;
  display: flex;
  flex-direction: column;
}

.feedback-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.feedback-text {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  flex: 1;
  margin-bottom: 12px;
}

.feedback-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.feedback-link:hover {
  color: var(--color-ink);
}

/* ==========================================================================
   Pages —— 常见问题 91cm/wenti.html
   ========================================================================== */

.intro-note {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 64px;
}

.intro-note .intro-figure {
  order: 1;
}

.intro-text {
  order: 2;
}

.intro-text .section-title {
  margin-bottom: 16px;
}

.intro-text p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 12px;
}

.intro-text p:last-child {
  margin-bottom: 0;
}

.faq-group {
  margin-bottom: 48px;
}

.faq-group .section-title {
  margin-bottom: 20px;
}

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

/* 反馈入口 */
.feedback-entry {
  margin-top: 64px;
  padding-top: 48px;
  border-top: 1px solid var(--color-line);
}

.feedback-entry .section-title {
  margin-bottom: 8px;
}

.feedback-entry > p {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 24px;
}

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

.feedback-card {
  padding: 24px 28px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.feedback-card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-ink);
}

.feedback-card-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
}

/* ==========================================================================
   Pages —— 内容边界 91cm/shuoming.html
   ========================================================================== */

.provided-section {
  margin-bottom: 64px;
}

.provided-section .section-heading {
  margin-bottom: 28px;
}

.provided-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.provided-media {
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 16 / 9;
  position: relative;
  box-shadow: var(--shadow-card);
}

.provided-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse at center,
    transparent 60%,
    rgba(0, 0, 0, 0.14) 100%
  );
  pointer-events: none;
}

.provided-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.provided-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.provided-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  padding: 20px 24px;
}

.provided-item h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 6px;
}

.provided-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
}

/* 不提供内容 */
.not-provided-section {
  margin-bottom: 64px;
}

.not-provided-section .section-heading {
  margin-bottom: 28px;
}

.not-provided-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.not-provided-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.not-provided-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.not-provided-item h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.not-provided-item p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
}

/* 核验建议 */
.verification-suggestion {
  margin-bottom: 16px;
}

.verification-suggestion .section-heading {
  margin-bottom: 28px;
}

.verification-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}

.verification-step {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.verification-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.verification-step .step-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
}

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

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

.verification-note {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.75;
}

.verification-note a {
  color: var(--color-accent);
  font-weight: 600;
}

.verification-note a:hover {
  color: var(--color-ink);
}

/* ==========================================================================
   Pages —— 404 错误页
   ========================================================================== */

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

.error-inner {
  max-width: 560px;
  text-align: center;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 72px;
  font-weight: 600;
  color: var(--color-accent);
  line-height: 1.2;
  margin-bottom: 16px;
}

.error-title {
  font-size: 28px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

.error-actions {
  margin-bottom: 48px;
}

.error-links {
  text-align: center;
}

.error-links-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-muted);
  margin-bottom: 12px;
}

.error-links ul {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}

.error-links ul li a {
  display: inline-block;
  padding: 6px 16px;
  font-size: 14px;
  color: var(--color-muted);
  border: 1px solid var(--color-line);
  border-radius: 100px;
  background-color: var(--color-surface);
}

.error-links ul li a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

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

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

  .hero-side {
    display: none;
  }

  .hero-media {
    aspect-ratio: 16 / 8;
  }

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

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

  .featured-sub-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
  }

  .featured-sub-card {
    flex-direction: column;
  }

  .featured-sub-card figure {
    width: 100%;
    aspect-ratio: 16 / 9;
  }

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

  .audience-list {
    grid-template-columns: repeat(3, 1fr);
  }

  .principle-items {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .not-provided-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .layout-shell,
  .sidebar-left {
    grid-template-columns: 180px 1fr;
    gap: 32px;
  }

  .maintenance-intro,
  .verification-layout,
  .intro-note,
  .provided-intro {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .intro-note .intro-figure {
    order: 0;
  }

  .intro-text {
    order: 1;
  }

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

/* 768px */
@media (max-width: 768px) {
  .header-inner {
    height: auto;
    min-height: var(--header-h);
    padding: 10px var(--container-pad);
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: flex;
  }

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

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    padding: 12px 0;
    gap: 2px;
  }

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

  .nav-list li a {
    padding: 12px 16px;
    font-size: 16px;
  }

  .inner-main {
    padding: 0 var(--container-pad) 64px;
  }

  .page-header {
    padding: 24px 0 32px;
    margin-bottom: 40px;
  }

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

  .layout-shell,
  .sidebar-left {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .anchor-nav {
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--color-line);
    padding: 0 0 20px;
  }

  .anchor-nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .anchor-nav ul li {
    margin-bottom: 0;
  }

  .anchor-nav ul li a {
    padding: 8px 16px;
    font-size: 14px;
    border: 1px solid var(--color-line);
    border-radius: 100px;
    background-color: var(--color-surface);
  }

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

  .hero {
    padding: 40px var(--container-pad) 56px;
  }

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

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

  .channel-overview,
  .featured-playlist,
  .path-strip,
  .recent-records,
  .faq-summary,
  .help-band {
    padding: 56px var(--container-pad);
  }

  .path-steps {
    grid-template-columns: 1fr;
  }

  .help-cards {
    grid-template-columns: 1fr;
  }

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

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

  .principle-items {
    grid-template-columns: 1fr;
  }

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

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

  .feedback-links {
    grid-template-columns: 1fr;
  }

  .not-provided-grid {
    grid-template-columns: 1fr;
  }

  .verification-steps {
    grid-template-columns: 1fr;
  }

  .featured-card {
    grid-template-columns: 1fr;
  }

  .featured-body {
    padding: 24px;
  }

  .related-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px var(--container-pad) 24px;
  }

  .footer-brand-desc {
    max-width: 100%;
  }
}

/* 480px */
@media (max-width: 480px) {
  :root {
    --container-pad: 16px;
  }

  .brand-name {
    font-size: 20px;
  }

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

  .hero-subtitle {
    font-size: 15px;
  }

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

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

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

  .featured-sub-cards {
    grid-template-columns: 1fr;
  }

  .faq-item summary {
    padding: 16px 18px;
    font-size: 15px;
  }

  .faq-answer {
    padding: 0 18px 18px;
    font-size: 14px;
  }

  .faq-preview-list .faq-item p {
    padding: 0 18px 16px;
    font-size: 14px;
  }

  .record-item {
    padding: 18px 20px;
  }

  .principle-item,
  .audience-item,
  .step-card,
  .verification-step,
  .not-provided-item,
  .help-card,
  .feedback-card {
    padding: 20px;
  }

  .current-status,
  .verification-note,
  .channel-tips {
    padding: 20px;
  }

  .playlist-info {
    padding: 16px 18px 18px;
  }

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

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