```css
/* ============================================
   古名影视 - 国产a高清播放平台
   风格: 科技蓝 + 深空渐变 + 毛玻璃 + 微动效
   适配: PC / Mobile / Dark Mode
   性能: 无外部依赖, 轻量级, GPU加速
   ============================================ */

/* ---------- CSS Reset & 基础变量 ---------- */
:root {
  /* 主色板 - 科技蓝 */
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --accent: #06b6d4;
  --accent-light: #22d3ee;

  /* 中性色 */
  --bg-light: #f5f7fb;
  --bg-dark: #0b1120;
  --surface-light: rgba(255, 255, 255, 0.75);
  --surface-dark: rgba(15, 23, 42, 0.75);
  --text-light: #1f2937;
  --text-dark: #e2e8f0;
  --heading-light: #0f172a;
  --heading-dark: #f8fafc;
  --subtext-light: #475569;
  --subtext-dark: #cbd5e1;

  /* 卡片/边框 */
  --card-bg-light: #ffffff;
  --card-bg-dark: rgba(30, 41, 59, 0.6);
  --border-light: rgba(15, 23, 42, 0.08);
  --border-dark: rgba(148, 163, 184, 0.15);

  /* 阴影 & 毛玻璃 */
  --shadow-light: 0 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-dark: 0 8px 32px rgba(0, 0, 0, 0.35);
  --glass-blur: blur(16px) saturate(180%);

  /* 圆角 */
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;

  /* 动效 */
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --transition-fast: 0.25s var(--ease-out);
  --transition-slow: 0.5s var(--ease-out);

  /* 间距 */
  --space-section: 80px;
  --space-card: 24px;

  /* 滚动动画初始状态 */
  --reveal-start: translateY(40px);
  --reveal-end: translateY(0);
}

/* 深色模式变量覆盖 */
body.dark-mode {
  --bg-light: var(--bg-dark);
  --text-light: var(--text-dark);
  --heading-light: var(--heading-dark);
  --subtext-light: var(--subtext-dark);
  --surface-light: var(--surface-dark);
  --card-bg-light: var(--card-bg-dark);
  --border-light: var(--border-dark);
  --shadow-light: var(--shadow-dark);
  color-scheme: dark;
}

/* ---------- 基础样式 ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 90px; /* 固定导航补偿 */
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial,
    'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-light);
  color: var(--text-light);
  line-height: 1.7;
  font-size: 16px;
  transition: background-color 0.5s ease, color 0.3s ease;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 渐变背景装饰 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.08) 0%, transparent 40%),
    radial-gradient(circle at 80% 0%, rgba(6, 182, 212, 0.05) 0%, transparent 35%);
  pointer-events: none;
  z-index: -1;
  transition: opacity 0.5s;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--heading-light);
  transition: color 0.3s;
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); margin-bottom: 1.5rem; }
h3 { font-size: 1.25rem; margin-bottom: 0.75rem; }
h4 { font-size: 1.05rem; }

p {
  color: var(--subtext-light);
  line-height: 1.75;
  transition: color 0.3s;
}

a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-light);
  text-decoration: underline;
  text-underline-offset: 4px;
}

body.dark-mode a:hover {
  color: var(--accent-light);
}

ul, ol {
  padding-left: 1.25rem;
  color: var(--subtext-light);
}

li {
  margin-bottom: 0.35rem;
}

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 滚动条美化 ---------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(100, 116, 139, 0.4);
  border-radius: 20px;
  border: 2px solid transparent;
  background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(100, 116, 139, 0.6);
  background-clip: content-box;
}

/* ---------- 滚动渐入动画 ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: var(--reveal-start);
  }
  to {
    opacity: 1;
    transform: var(--reveal-end);
  }
}

/* 卡片默认隐藏，通过 JS 添加 .in-view 类触发 */
.fade-in-up {
  animation: fadeInUp 0.8s var(--ease-out) both;
}

/* 基础卡片通用样式 */
.card,
.article-card,
.faq-item {
  background: var(--surface-light);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-light);
  transition: transform 0.4s var(--ease-out), box-shadow 0.4s ease,
    background-color 0.4s ease, border-color 0.3s ease;
  will-change: transform;
  position: relative;
  overflow: hidden;
}

.card::after,
.article-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0;
  transition: opacity 0.4s ease;
}

.card:hover::after,
.article-card:hover::after {
  opacity: 1;
}

.card:hover,
.article-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.15);
}

body.dark-mode .card:hover,
body.dark-mode .article-card:hover {
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.card h3,
.article-card h3 {
  color: var(--heading-light);
  margin-bottom: 12px;
  font-size: 1.35rem;
  position: relative;
  display: inline-block;
}

.card h3::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 30%;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 4px;
  transition: width 0.4s var(--ease-out);
}

.card:hover h3::after {
  width: 100%;
}

/* ---------- 固定导航栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  background: var(--surface-light);
  border-bottom: 1px solid var(--border-light);
  transition: background-color 0.4s ease, border-color 0.3s ease;
}

body.dark-mode .site-header {
  background: rgba(11, 17, 32, 0.85);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  max-width: 1400px;
  margin: 0 auto;
  position: relative;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.03em;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.logo span {
  font-size: 0.9rem;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 600;
  margin-left: 4px;
}

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

.nav-links a {
  color: var(--text-light);
  font-weight: 500;
  padding: 8px 14px;
  border-radius: 50px;
  transition: background-color 0.3s, color 0.3s, transform 0.2s;
  font-size: 0.95rem;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 4px;
  transition: width 0.3s var(--ease-out);
}

.nav-links a:hover {
  color: var(--primary);
  background: rgba(37, 99, 235, 0.08);
  text-decoration: none;
}

.nav-links a:hover::after {
  width: 60%;
}

body.dark-mode .nav-links a:hover {
  color: var(--accent-light);
  background: rgba(6, 182, 212, 0.1);
}

.theme-toggle {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s ease;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.theme-toggle:hover {
  transform: scale(1.05) translateY(-2px);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

.theme-toggle:active {
  transform: scale(0.95);
}

body.dark-mode .theme-toggle {
  background: linear-gradient(135deg, #0ea5e9, #6366f1);
}

/* ---------- Hero 首屏 ---------- */
.hero {
  position: relative;
  padding: calc(var(--space-section) * 1.2) 24px;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
  overflow: hidden;
  isolation: isolate;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(37, 99, 235, 0.4) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(6, 182, 212, 0.3) 0%, transparent 40%),
    radial-gradient(ellipse at 50% 100%, rgba(99, 102, 241, 0.2) 0%, transparent 50%);
  z-index: -1;
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% { opacity: 0.6; transform: scale(1); }
  100% { opacity: 1; transform: scale(1.2); }
}

.hero .container {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero h1 {
  color: #ffffff;
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  text-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
  background: linear-gradient(135deg, #ffffff 0%, #e0f2fe 50%, #bae6fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  color: rgba(255, 255, 255, 0.85);
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  max-width: 800px;
  margin: 0 auto 30px;
  line-height: 1.6;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero svg {
  max-width: 900px;
  margin: 40px auto 0;
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
  transition: transform 0.6s var(--ease-out);
}

.hero svg:hover {
  transform: scale(1.02);
}

/* 返回顶部按钮 */
#backToTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 999;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  padding: 14px 18px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  box-shadow: 0 10px 30px rgba(37, 99, 235, 0.3);
  transition: all 0.3s var(--ease-out);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

#backToTop.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

#backToTop:hover {
  transform: translateY(-5px) scale(1.05);
}

/* ---------- 区块样式 ---------- */
section[id] {
  scroll-margin-top: 90px;
}

section {
  padding: var(--space-section) 0;
}

section:first-of-type {
  padding-top: calc(var(--space-section) * 0.8);
}

section h2 {
  position: relative;
  display: inline-block;
  margin-bottom: 40px;
  padding-bottom: 16px;
}

section h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 8px;
}

/* 网格布局 */
.grid-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 28px;
  margin-top: 20px;
}

/* 产品区域特殊样式 */
#products .container > div:not(.grid-list) {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

/* FAQ 样式 */
.faq-item {
  margin-bottom: 16px;
  padding: 24px 28px;
  cursor: pointer;
  border-radius: var(--radius-md);
  background: var(--surface-light);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-light);
  transition: all 0.3s var(--ease-out);
}

.faq-item:hover {
  border-color: var(--primary);
  transform: translateX(8px);
}

.faq-question {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--heading-light);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  cursor: pointer;
  transition: color 0.3s;
}

.faq-question::before {
  content: 'Q';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 800;
  flex-shrink: 0;
}

.faq-answer {
  padding-left: 40px;
  display: none;
  animation: fadeInUp 0.4s var(--ease-out);
  color: var(--subtext-light);
  line-height: 1.8;
}

.faq-answer::before {
  content: 'A';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: rgba(6, 182, 212, 0.15);
  color: var(--accent);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 800;
  margin-right: 10px;
}

.faq-item.active .faq-answer {
  display: block;
}

.faq-item.active .faq-question {
  color: var(--primary);
}

/* 引文样式 */
blockquote {
  border-left: 4px solid var(--primary);
  background: var(--surface-light);
  padding: 24px 28px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 32px 0;
  font-style: italic;
  position: relative;
  box-shadow: var(--shadow-light);
  backdrop-filter: blur(8px);
}

blockquote::before {
  content: '"';
  position: absolute;
  top: -20px;
  left: 10px;
  font-size: 4rem;
  color: var(--primary);
  opacity: 0.2;
}

/* 文章卡片特殊处理 */
.article-card {
  display: flex;
  flex-direction: column;
}

.article-card p {
  flex-grow: 1;
  margin-bottom: 16px;
}

.article-card a {
  align-self: flex-start;
  font-weight: 600;
  position: relative;
  padding-bottom: 2px;
  transition: all 0.3s;
}

.article-card a::after {
  content: ' →';
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.3s;
  display: inline-block;
}

.article-card a:hover::after {
  opacity: 1;
  transform: translateX(0);
}

/* HowTo 区域 */
#howto > .container > div {
  background: var(--surface-light);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow-light);
  line-height: 1.8;
}

#howto ol {
  padding-left: 1.5rem;
}

#howto li {
  margin-bottom: 12px;
  padding-left: 8px;
  position: relative;
}

#howto li::marker {
  color: var(--primary);
  font-weight: 700;
}

/* 联系区域 */
#contact .container > div {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  align-items: start;
}

#contact svg {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-light);
  transition: transform 0.4s var(--ease-out);
}

#contact svg:hover {
  transform: scale(1.02);
}

/* ---------- Footer ---------- */
.footer {
  background: var(--surface-light);
  backdrop-filter: var(--glass-blur);
  border-top: 1px solid var(--border-light);
  padding: 48px 0 24px;
  margin-top: 80px;
  transition: background-color 0.4s ease;
}

body.dark-mode .footer {
  background: rgba(11, 17, 32, 0.8);
}

.footer h4 {
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.footer ul {
  list-style: none;
  padding: 0;
}

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

.footer ul a {
  color: var(--subtext-light);
  transition: color 0.3s, padding-left 0.3s;
  position: relative;
}

.footer ul a:hover {
  color: var(--primary);
  padding-left: 8px;
  text-decoration: none;
}

.footer p {
  font-size: 0.95rem;
}

.footer .container > div:first-child {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 32px;
}

/* ---------- 移动端适配 ---------- */
@media (max-width: 768px) {
  :root {
    --space-section: 50px;
    --space-card: 18px;
  }

  .navbar {
    padding: 12px 16px;
    flex-wrap: wrap;
    gap: 10px;
  }

  .nav-links {
    order: 3;
    width: 100%;
    display: none;
    flex-direction: column;
    align-items: flex-start;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    width: 100%;
    padding: 10px 0;
    border-radius: 0;
  }

  .nav-links a::after {
    display: none;
  }

  .logo {
    font-size: 1.3rem;
  }

  .theme-toggle {
    margin-left: auto;
    padding: 8px 16px;
    font-size: 0.85rem;
  }

  .hero {
    padding: 60px 16px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .container {
    padding: 0 16px;
  }

  .grid-list {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .card,
  .article-card,
  .faq-item {
    padding: 20px;
    border-radius: var(--radius-md);
  }

  .faq-question {
    font-size: 1rem;
  }

  .faq-answer {
    padding-left: 0;
    font-size: 0.95rem;
  }

  #howto .container > div {
    padding: 24px;
  }

  #contact .container > div {
    grid-template-columns: 1fr;
  }

  blockquote {
    padding: 16px 20px;
    font-size: 0.95rem;
  }

  .footer {
    padding: 32px 0 16px;
  }

  .footer .container > div:first-child {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  #backToTop {
    bottom: 20px;
    right: 20px;
    padding: 12px 16px;
    font-size: 0.85rem;
  }
}

@media (max-width: 480px) {
  .logo span {
    display: none;
  }

  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.4rem; }
  h3 { font-size: 1.1rem; }

  .hero svg {
    margin-top: 20px;
  }
}

/* ---------- 暗色模式额外细节 ---------- */
body.dark-mode .faq-item {
  background: rgba(15, 23, 42, 0.6);
}

body.dark-mode .faq-question {
  color: #f1f5f9;
}

body.dark-mode .faq-answer {
  color: #cbd5e1;
}

body.dark-mode .card h3 {
  color: #f1f5f9;
}

body.dark-mode .article-card h3 {
  color: #f1f5f9;
}

/* ---------- 无障碍 & 焦点 ---------- */
:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}
```