```css
/* ==========================================================================
   零度环境 · 免费高清视频 - 主样式表
   设计风格：深蓝科技 · 渐变玻璃拟态
   适配：PC / 平板 / 手机 / 暗色模式
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. 设计令牌（CSS 变量）
   -------------------------------------------------------------------------- */
:root {
  /* 品牌色 */
  --brand: #0b3d91;
  --brand-2: #1e5bb8;
  --brand-3: #4fc3f7;
  --brand-glow: rgba(79, 195, 247, 0.45);

  /* 强调色 */
  --accent: #ff6b6b;
  --accent-2: #feca57;
  --success: #34d399;

  /* 中性色 - 亮色模式 */
  --bg: #f4f7fc;
  --bg-soft: #eaf0fa;
  --surface: #ffffff;
  --surface-2: #f9fbff;
  --text: #17233d;
  --text-2: #4a5878;
  --text-3: #7a87a3;
  --border: rgba(11, 61, 145, 0.12);
  --border-strong: rgba(11, 61, 145, 0.22);

  /* 玻璃拟态 */
  --glass-bg: rgba(255, 255, 255, 0.62);
  --glass-border: rgba(255, 255, 255, 0.75);
  --glass-blur: 16px;

  /* 渐变 */
  --grad-hero: linear-gradient(135deg, #0b3d91 0%, #1e5bb8 45%, #4fc3f7 100%);
  --grad-hero-soft: linear-gradient(135deg, rgba(11, 61, 145, 0.92) 0%, rgba(30, 91, 184, 0.86) 50%, rgba(79, 195, 247, 0.78) 100%);
  --grad-btn: linear-gradient(135deg, #1e5bb8 0%, #4fc3f7 100%);
  --grad-accent: linear-gradient(135deg, #ff6b6b 0%, #feca57 100%);
  --grad-line: linear-gradient(90deg, transparent, var(--brand-3), transparent);

  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(11, 61, 145, 0.08);
  --shadow-md: 0 8px 24px rgba(11, 61, 145, 0.12);
  --shadow-lg: 0 18px 48px rgba(11, 61, 145, 0.18);
  --shadow-glow: 0 8px 32px var(--brand-glow);

  /* 圆角 */
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 24px;
  --r-xl: 32px;
  --r-pill: 999px;

  /* 间距 */
  --space-xs: 0.5rem;
  --space-sm: 0.875rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  /* 布局 */
  --container: 1200px;
  --header-h: 72px;

  /* 动效 */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --dur: 0.35s;

  /* 字体 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
}

/* 暗色模式 */
[data-theme="dark"],
html.dark {
  --bg: #070d1a;
  --bg-soft: #0c1526;
  --surface: #101c33;
  --surface-2: #14223c;
  --text: #e8eefb;
  --text-2: #a9b8d6;
  --text-3: #6f7f9f;
  --border: rgba(79, 195, 247, 0.14);
  --border-strong: rgba(79, 195, 247, 0.28);

  --glass-bg: rgba(16, 28, 51, 0.55);
  --glass-border: rgba(79, 195, 247, 0.22);

  --grad-hero: linear-gradient(135deg, #061029 0%, #0b3d91 45%, #1e5bb8 100%);
  --grad-hero-soft: linear-gradient(135deg, rgba(6, 16, 41, 0.94) 0%, rgba(11, 61, 145, 0.88) 50%, rgba(30, 91, 184, 0.8) 100%);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 18px 48px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 8px 32px rgba(79, 195, 247, 0.25);
}

/* 跟随系统暗色（未手动切换时） */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #070d1a;
    --bg-soft: #0c1526;
    --surface: #101c33;
    --surface-2: #14223c;
    --text: #e8eefb;
    --text-2: #a9b8d6;
    --text-3: #6f7f9f;
    --border: rgba(79, 195, 247, 0.14);
    --border-strong: rgba(79, 195, 247, 0.28);
    --glass-bg: rgba(16, 28, 51, 0.55);
    --glass-border: rgba(79, 195, 247, 0.22);
    --grad-hero: linear-gradient(135deg, #061029 0%, #0b3d91 45%, #1e5bb8 100%);
    --grad-hero-soft: linear-gradient(135deg, rgba(6, 16, 41, 0.94) 0%, rgba(11, 61, 145, 0.88) 50%, rgba(30, 91, 184, 0.8) 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 18px 48px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 8px 32px rgba(79, 195, 247, 0.25);
  }
}

/* --------------------------------------------------------------------------
   2. 基础重置
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 12% 8%, rgba(79, 195, 247, 0.10), transparent 42%),
    radial-gradient(circle at 88% 22%, rgba(30, 91, 184, 0.10), transparent 46%),
    radial-gradient(circle at 50% 100%, rgba(11, 61, 145, 0.08), transparent 55%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

a {
  color: var(--brand-2);
  text-decoration: none;
  transition: color 0.25s var(--ease), opacity 0.25s var(--ease);
}

a:hover {
  color: var(--brand-3);
}

ul,
ol {
  padding-left: 1.25rem;
  margin: 0 0 var(--space-md);
}

p {
  margin: 0 0 var(--space-md);
  color: var(--text-2);
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-sm);
  color: var(--text);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(1.75rem, 4.2vw, 3rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2.15rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }

strong {
  color: var(--text);
  font-weight: 700;
}

::selection {
  background: var(--brand-3);
  color: #061029;
}

/* 焦点可见性 */
:focus-visible {
  outline: 3px solid var(--brand-3);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 滚动条 */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: var(--bg-soft);
}
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--brand-2), var(--brand-3));
  border-radius: var(--r-pill);
  border: 2px solid var(--bg-soft);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--brand-3);
}

/* 无障碍隐藏 */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   3. 通用滚动动画
   -------------------------------------------------------------------------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(28px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 0 0 var(--brand-glow); }
  50% { box-shadow: 0 0 0 12px rgba(79, 195, 247, 0); }
}

/* 默认进入动画（无需 JS 也可见，JS 可加 .is-visible 控制） */
section,
article,
.news-list > li,
.testimonial-list > li {
  animation: fadeUp 0.7s var(--ease-out) both;
}

section:nth-of-type(2n) { animation-delay: 0.05s; }
section:nth-of-type(3n) { animation-delay: 0.1s; }

/* JS 控制：初始隐藏，进入视口显示 */
.js-reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
  will-change: opacity, transform;
}
.js-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* --------------------------------------------------------------------------
   4. 布局容器
   -------------------------------------------------------------------------- */
main {
  display: block;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 clamp(1rem, 4vw, 2.5rem);
}

main > section {
  margin-bottom: clamp(2.5rem, 6vw, 5rem);
}

/* 卡片通用 */
main > section > article,
main > section > dl,
main > section > ul,
main > section > address,
main > section > figure,
main > section > div {
  position: relative;
}

/* --------------------------------------------------------------------------
   5. 头部 Header
   -------------------------------------------------------------------------- */
#site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

#site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: var(--grad-line);
  opacity: 0.6;
}

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 clamp(1rem, 4vw, 2.5rem);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Logo */
.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 800;
  color: var(--text);
  flex-shrink: 0;
  transition: transform 0.3s var(--ease);
}

.logo:hover {
  transform: translateY(-1px);
}

.logo svg {
  border-radius: 12px;
  box-shadow: var(--shadow-glow);
  transition: transform 0.5s var(--ease), box-shadow 0.35s var(--ease);
}

.logo:hover svg {
  transform: rotate(-6deg) scale(1.05);
  box-shadow: 0 10px 28px var(--brand-glow);
}

.logo-text {
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}

[data-theme="dark"] .logo-text,
html.dark .logo-text {
  background: linear-gradient(135deg, #cfe6ff 0%, var(--brand-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 导航 */
#site-header nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.nav-list a {
  display: inline-block;
  position: relative;
  padding: 0.45rem 0.75rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-2);
  border-radius: var(--r-pill);
  transition: color 0.25s var(--ease), background 0.25s var(--ease), transform 0.25s var(--ease);
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-btn);
  transform: translateX(-50%);
  transition: width 0.3s var(--ease);
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--brand-2);
  background: rgba(79, 195, 247, 0.12);
  transform: translateY(-1px);
}

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

/* 头部操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: auto;
  flex-shrink: 0;
}

/* 搜索 */
.search-form {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 3px 3px 3px 14px;
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

.search-form:focus-within {
  border-color: var(--brand-3);
  box-shadow: 0 0 0 4px rgba(79, 195, 247, 0.18);
}

.search-form input[type="search"] {
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-family: inherit;
  font-size: 0.875rem;
  width: 150px;
  padding: 0.45rem 0;
  transition: width 0.35s var(--ease);
}

.search-form input[type="search"]::placeholder {
  color: var(--text-3);
}

.search-form input[type="search"]:focus {
  width: 200px;
}

.search-form input[type="search"]::-webkit-search-cancel-button {
  cursor: pointer;
}

.search-form button {
  border: 0;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  padding: 0.45rem 1rem;
  border-radius: var(--r-pill);
  background: var(--grad-btn);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), filter 0.25s var(--ease);
}

.search-form button:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
  filter: brightness(1.08);
}

.search-form button:active {
  transform: translateY(0) scale(0.98);
}

/* 主题切换 / 菜单按钮 */
#theme-toggle,
#menu-toggle {
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 0.5rem 1rem;
  white-space: nowrap;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease), background 0.25s var(--ease), transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

#theme-toggle:hover,
#menu-toggle:hover {
  color: var(--brand-2);
  border-color: var(--brand-3);
  background: rgba(79, 195, 247, 0.1);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

#theme-toggle:active,
#menu-toggle:active {
  transform: translateY(0) scale(0.97);
}

#menu-toggle {
  display: none;
}

/* --------------------------------------------------------------------------
   6. 面包屑
   -------------------------------------------------------------------------- */
.breadcrumb {
  margin: var(--space-md) 0 var(--space-lg);
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  color: var(--text-3);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  box-shadow: var(--shadow-sm);
  width: fit-content;
  max-width: 100%;
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.breadcrumb li + li::before {
  content: "›";
  color: var(--text-3);
  font-weight: 700;
  margin-right: 0.15rem;
}

.breadcrumb a {
  color: var(--text-2);
  font-weight: 500;
}

.breadcrumb a:hover {
  color: var(--brand-3);
}

.breadcrumb [aria-current="page"] {
  color: var(--brand-2);
  font-weight: 600;
}

[data-theme="dark"] .breadcrumb [aria-current="page"],
html.dark .breadcrumb [aria-current="page"] {
  color: var(--brand-3);
}

/* --------------------------------------------------------------------------
   7. Hero 渐变 Banner
   -------------------------------------------------------------------------- */
#hero {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: clamp(1.5rem, 5vw, 4rem);
  align-items: center;
  padding: clamp(2rem, 5vw, 4rem);
  border-radius: var(--r-xl);
  background: var(--grad-hero);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  isolation: isolate;
}

#hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 15% 20%, rgba(255, 255, 255, 0.22), transparent 45%),
    radial-gradient(circle at 85% 80%, rgba(79, 195, 247, 0.35), transparent 50%),
    radial-gradient(circle at 50% 0%, rgba(255, 255, 255, 0.12), transparent 60%);
  z-index: -1;
  pointer-events: none;
}

#hero::after {
  content: "";
  position: absolute;
  top: -120px;
  right: -120px;
  width: 340px;
  height: 340px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79, 195, 247, 0.55), transparent 70%);
  filter: blur(30px);
  z-index: -1;
  animation: floatY 8s ease-in-out infinite;
  pointer-events: none;
}

.hero-content {
  max-width: 640px;
  animation: fadeUp 0.9s var(--ease-out) both;
}

#hero-title {
  color: #fff;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.25);
  margin-bottom: var(--space-md);
}

.hero-lead {
  color: rgba(255, 255, 255, 0.9);
  font-size: clamp(0.95rem, 1.6vw, 1.1rem);
  line-height: 1.85;
  margin-bottom: var(--space-md);
}

.hero-keywords {
  display: inline-block;
  padding: 0.5rem 1.1rem;
  font-size: 0.85rem;
  color: #eaf6ff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: var(--r-pill);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  margin-bottom: var(--space-lg);
}

.hero-keywords strong {
  color: #fff;
  font-weight: 700;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

/* 按钮 */
.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 2rem;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--r-pill);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease), border-color 0.3s var(--ease);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.btn-primary {
  color: #fff;
  background: var(--grad-btn);
  box-shadow: 0 10px 28px rgba(79, 195, 247, 0.4);
}

.btn-primary::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255, 255, 255, 0.5) 50%, transparent 70%);
  background-size: 200% 100%;
  transform: translateX(-100%);
  transition: transform 0.7s var(--ease);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 16px 36px rgba(79, 195, 247, 0.55);
}

.btn-primary:hover::before {
  transform: translateX(100%);
}

.btn-secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.5);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  color: var(--brand);
  background: #fff;
  transform: translateY(-3px);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.25);
}

.btn-primary:active,
.btn-secondary:active {
  transform: translateY(-1px) scale(0.98);
}

/* Hero 视觉 */
.hero-visual {
  margin: 0;
  position: relative;
  animation: fadeIn 1.1s var(--ease-out) 0.15s both;
}

.hero-visual svg {
  width: 100%;
  height: auto;
  border-radius: var(--r-lg);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
  transition: transform 0.6s var(--ease), box-shadow 0.6s var(--ease);
  animation: floatY 7s ease-in-out infinite;
}

.hero-visual:hover svg {
  transform: translateY(-6px) scale(1.015);
  box-shadow: 0 32px 72px rgba(0, 0, 0, 0.4);
}

.hero-visual figcaption {
  margin-top: var(--space-sm);
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.75);
  text-align: center;
  letter-spacing: 0.02em;
}

/* --------------------------------------------------------------------------
   8. 数据统计
   -------------------------------------------------------------------------- */
#stats {
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border-radius: var(--r-lg);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow-md);
}

#stats-title {
  text-align: center;
  margin-bottom: var(--space-lg);
  position: relative;
  display: inline-block;
  left: 50%;
  transform: translateX(-50%);
}

#stats-title::after {
  content: "";
  display: block;
  width: 56px;
  height: 4px;
  margin: 0.6rem auto 0;
  border-radius: var(--r-pill);
  background: var(--grad-btn);
}

.stats-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.stats-list li {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: var(--space-md) var(--space-sm);
  border-radius: var(--r-md);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
  overflow: hidden;
}

.stats-list li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--grad-btn);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease);
}

.stats-list li:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--brand-3);
}

.stats-list li:hover::before {
  transform: scaleX(1);
}

.stat-num {
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
  font-weight: 800;
  line-height: 1;
  font-family: var(--font-mono);
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.02em;
}

[data-theme="dark"] .stat-num,
html.dark .stat-num {
  background: linear-gradient(135deg, #8fd0ff 0%, var(--brand-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-3);
  text-align: center;
}

/* --------------------------------------------------------------------------
   9. 通用内容区块
   -------------------------------------------------------------------------- */
main > section > h2 {
  position: relative;
  padding-left: 1.1rem;
  margin-bottom: var(--space-lg);
}

main > section > h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 1.1em;
  border-radius: var(--r-pill);
  background: var(--grad-btn);
  box-shadow: 0 0 12px var(--brand-glow);
}

main > section > article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: clamp(1.25rem, 3.5vw, 2.5rem);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.4s var(--ease), transform 0.4s var(--ease), border-color 0.4s var(--ease);
}

main > section > article:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-strong);
}

main > section > article h3 {
  position: relative;
  padding-bottom: 0.5rem;
  margin-top: var(--space-lg);
  color: var(--brand-2);
}

main > section > article h3:first-child {
  margin-top: 0;
}

[data-theme="dark"] main > section > article h3,
html.dark main > section > article h3 {
  color: var(--brand-3);
}

main > section > article h3::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 36px;
  height: 3px;
  border-radius: var(--r-pill);
  background: var(--grad-btn);
  opacity: 0.7;
}

main > section > article p:last-child {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   10. 列表通用（新闻 / 评价 / 链接 / 地图）
   -------------------------------------------------------------------------- */
.news-list,
.testimonial-list,
.sitemap-list,
.friend-links {
  list-style: none;
  margin: 0;
  padding: 0;
}

/* 新闻 */
.news-list {
  display: grid;
  gap: var(--space-md);
}

.news-list > li {
  position: relative;
  padding: var(--space-md) var(--space-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
  overflow: hidden;
}

.news-list > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--grad-btn);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.4s var(--ease);
}

.news-list > li:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
  border-color: var(--brand-3);
}

.news-list > li:hover::before {
  transform: scaleY(1);
}

.news-list h3 {
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.news-list h3 a {
  color: var(--text);
  transition: color 0.25s var(--ease);
}

.news-list h3 a:hover {
  color: var(--brand-3);
}

.news-list time {
  display: inline-block;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--text-3);
  padding: 0.15rem 0.6rem;
  border-radius: var(--r-pill);
  background: var(--bg-soft);
  margin-bottom: 0.5rem;
}

.news-list p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--text-2);
}

/* 客户评价 */
.testimonial-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.testimonial-list > li {
  position: relative;
  padding: var(--space-lg) var(--space-md) var(--space-md);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), border-color 0.4s var(--ease);
}

.testimonial-list > li::before {
  content: "“";
  position: absolute;
  top: -6px;
  left: 18px;
  font-size: 4.5rem;
  line-height: 1;
  font-family: Georgia, "Times New Roman", serif;
  color: var(--brand-3);
  opacity: 0.35;
  pointer-events: none;
}

.testimonial-list > li:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--brand-3);
}

.testimonial-list blockquote {
  margin: 0 0 var(--space-sm);
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-2);
  position: relative;
  z-index: 1;
}

.testimonial-list cite {
  display: block;
  font-style: normal;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--brand-2);
  text-align: right;
}

[data-theme="dark"] .testimonial-list cite,
html.dark .testimonial-list cite {
  color: var(--brand-3);
}

/* --------------------------------------------------------------------------
   11. 技术文章
   -------------------------------------------------------------------------- */
#articles > article {
  margin-bottom: var(--space-md);
}

#articles > article:last-child {
  margin-bottom: 0;
}

#articles > article h3 {
  margin-top: 0;
  font-size: 1.2rem;
  color: var(--text);
}

#articles > article h3::after {
  display: none;
}

#articles > article .meta {
  font-size: 0.8rem;
  color: var(--text-3);
  font-family: var(--font-mono);
  padding-bottom: var(--space-sm);
  margin-bottom: var(--space-sm);
  border-bottom: 1px dashed var(--border);
}

#articles > article p:not(.meta) {
  font-size: 0.95rem;
  line-height: 1.9;
  color: var(--text-2);
}

/* --------------------------------------------------------------------------
   12. FAQ
   -------------------------------------------------------------------------- */
.faq-list {
  margin: 0;
  display: grid;
  gap: var(--space-sm);
}

.faq-list dt {
  margin: 0;
}

.faq-list dt button {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  text-align: left;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 1rem 1.25rem;
  cursor: pointer;
  position: relative;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), transform 0.3s var(--ease);
}

.faq-list dt button::after {
  content: "+";
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--brand-2);
  background: rgba(79, 195, 247, 0.14);
  transition: transform 0.35s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
}

.faq-list dt button:hover {
  background: var(--surface-2);
  border-color: var(--brand-3);
  box-shadow: var(--shadow-sm);
}

.faq-list dt button[aria-expanded="true"] {
  border-color: var(--brand-3);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  background: linear-gradient(135deg, rgba(79, 195, 247, 0.12), rgba(30, 91, 184, 0.06));
}

.faq-list dt button[aria-expanded="true"]::after {
  content: "−";
  transform: rotate(180deg);
  background: var(--grad-btn);
  color: #fff;
}

.faq-list dd {
  margin: 0;
  padding: 0 1.25rem;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 0.94rem;
  line-height: 1.85;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid transparent;
  border-top: 0;
  border-bottom-left-radius: var(--r-md);
  border-bottom-right-radius: var(--r-md);
  transition: max-height 0.45s var(--ease), opacity 0.35s var(--ease), padding 0.35s var(--ease), border-color 0.35s var(--ease);
}

.faq-list dd.is-open,
.faq-list dt button[aria-expanded="true"] + dd {
  max-height: 800px;
  opacity: 1;
  padding: 0.25rem 1.25rem 1.25rem;
  border-color: var(--border);
  border-top-color: transparent;
}

/* --------------------------------------------------------------------------
   13. 使用教程
   -------------------------------------------------------------------------- */
#howto article ol {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
  display: grid;
  gap: var(--space-sm);
}

#howto article ol li {
  position: relative;
  padding: 0.85rem 1rem 0.85rem 3.4rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  font-size: 0.95rem;
  color: var(--text-2);
  counter-increment: step;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}

#howto article ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: #fff;
  background: var(--grad-btn);
  box-shadow: 0 4px 12px rgba(79, 195, 247, 0.35);
}

#howto article ol li:hover {
  transform: translateX(6px);
  border-color: var(--brand-3);
  box-shadow: var(--shadow-sm);
}

/* --------------------------------------------------------------------------
   14. 联系我们
   -------------------------------------------------------------------------- */
#contact address {
  font-style: normal;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm) var(--space-lg);
  padding: clamp(1.25rem, 3.5vw, 2.5rem);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-md);
}

#contact address p {
  margin: 0;
  padding: 0.75rem 1rem;
  font-size: 0.92rem;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

#contact address p:hover {
  transform: translateY(-3px);
  border-color: var(--brand-3);
  box-shadow: var(--shadow-sm);
}

#contact address a {
  font-weight: 600;
  color: var(--brand-2);
  border-bottom: 1px dashed currentColor;
}

#contact address a:hover {
  color: var(--brand-3);
}

[data-theme="dark"] #contact address a,
html.dark #contact address a {
  color: var(--brand-3);
}

/* --------------------------------------------------------------------------
   15. 网站地图 & 友情链接
   -------------------------------------------------------------------------- */
.sitemap-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.sitemap-list li {
  flex: 0 0 auto;
}

.sitemap-list a {
  display: inline-block;
  padding: 0.5rem 1.1rem;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  transition: all 0.3s var(--ease);
}

.sitemap-list a:hover {
  color: #fff;
  background: var(--grad-btn);
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

.friend-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.friend-links a {
  display: block;
  padding: 1rem 1.25rem;
  font-size: 0.92rem;
  font-weight: 600;
  text-align: center;
  color: var(--text-2);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  position: relative;
  overflow: hidden;
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease), transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.friend-links a::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--grad-btn);
  opacity: 0;
  z-index: -1;
  transition: opacity 0.35s var(--ease);
}

.friend-links a:hover {
  color: #fff;
  border-color: transparent;
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.friend-links a:hover::after {
  opacity: 1;
}

/* --------------------------------------------------------------------------
   16. 页脚
   -------------------------------------------------------------------------- */
#site-footer {
  margin-top: clamp(3rem, 7vw, 6rem);
  padding: clamp(2rem, 5vw, 4rem) clamp(1rem, 4vw, 2.5rem) var(--space-md);
  background: linear-gradient(180deg, transparent 0%, var(--bg-soft) 40%);
  border-top: 1px solid var(--border);
  position: relative;
}

#site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: min(90%, 720px);
  height: 1px;
  background: var(--grad-line);
}

#site-footer > section {
  max-width: var(--container);
  margin: 0 auto var(--space-lg);
}

#site-footer h2 {
  font-size: 1.05rem;
  position: relative;
  padding-left: 0.9rem;
  margin-bottom: var(--space-sm);
}

#site-footer h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 1em;
  border-radius: var(--r-pill);
  background: var(--grad-btn);
}

#site-footer h3 {
  font-size: 0.92rem;
  color: var(--brand-2);
  margin-top: var(--space-md);
}

[data-theme="dark"] #site-footer h3,
html.dark #site-footer h3 {
  color: var(--brand-3);
}

#site-footer p {
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--text-3);
}

#site-footer section[aria-labelledby="footer-legal"] {
  padding: var(--space-md) var(--space-lg);
  background: var(--glass-bg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
}

.footer-bottom {
  max-width: var(--container);
  margin: var(--space-lg) auto 0;
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-bottom p {
  margin: 0.25rem 0;
  font-size: 0.8rem;
  color: var(--text-3);
}

/* --------------------------------------------------------------------------
   17. 返回顶部
   -------------------------------------------------------------------------- */
#back-to-top {
  position: fixed;
  right: clamp(1rem, 3vw, 2rem);
  bottom: clamp(1rem, 3vw, 2rem);
  z-index: 900;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.3);
  cursor: pointer;
  font-size: 0;
  color: transparent;
  background: var(--grad-btn);
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px) scale(0.9);
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease), visibility 0.35s var(--ease), box-shadow 0.35s var(--ease);
  animation: pulseGlow 3s ease-in-out infinite;
}

#back-to-top::before {
  content: "↑";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
}

#back-to-top.show,
#back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

#back-to-top:hover {
  transform: translateY(-4px) scale(1.06);
  box-shadow: 0 16px 40px var(--brand-glow);
}

#back-to-top:active {
  transform: translateY(-2px) scale(0.98);
}

/* --------------------------------------------------------------------------
   18. 响应式 - 大屏
   -------------------------------------------------------------------------- */
@media (min-width: 1440px) {
  :root {
    --container: 1320px;
  }
}

/* --------------------------------------------------------------------------
   19. 响应式 - 中屏 / 平板
   -------------------------------------------------------------------------- */
@media (max-width: 1100px) {
  #hero {
    grid-template-columns: 1fr;
    text-align: left;
  }

  .hero-visual {
    max-width: 640px;
    margin: 0 auto;
    width: 100%;
  }

  .hero-visual svg {
    animation: none;
  }

  .nav-list a {
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
  }

  .search-form input[type="search"] {
    width: 120px;
  }

  .search-form input[type="search"]:focus {
    width: 160px;
  }
}

@media (max-width: 960px) {
  :root {
    --header-h: auto;
  }

  .header-inner {
    padding-top: 0.75rem;
    padding-bottom: 0.75rem;
    gap: 0.75rem;
  }

  #site-header nav {
    order: 3;
    flex: 1 1 100%;
  }

  .nav-list {
    gap: 0.25rem;
    padding-bottom: 0.25rem;
    overflow-x: auto;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .nav-list::-webkit-scrollbar {
    display: none;
  }

  .nav-list li {
    flex: 0 0 auto;
  }

  .header-actions {
    margin-left: auto;
  }

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

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

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

  #contact address {
    grid-template-columns: 1fr;
  }
}

/* --------------------------------------------------------------------------
   20. 响应式 - 手机
   -------------------------------------------------------------------------- */
@media (max-width: 720px) {
  body {
    font-size: 15px;
  }

  main {
    padding: 0 1rem;
  }

  #hero {
    padding: 1.75rem 1.25rem;
    border-radius: var(--r-lg);
    gap: 1.5rem;
  }

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

  .btn-primary,
  .btn-secondary {
    width: 100%;
    padding: 0.85rem 1.25rem;
  }

  .hero-keywords {
    display: block;
    text-align: center;
    font-size: 0.8rem;
  }

  .search-form {
    flex: 1 1 auto;
  }

  .search-form input[type="search"],
  .search-form input[type="search"]:focus {
    width: 100%;
    min-width: 0;
  }

  #theme-toggle,
  #menu-toggle {
    padding: 0.5rem 0.75rem;
    font-size: 0.78rem;
  }

  #menu-toggle {
    display: inline-block;
  }

  .header-inner {
    flex-wrap: wrap;
  }

  .logo-text {
    font-size: 0.92rem;
  }

  .breadcrumb {
    margin: 1rem 0 1.5rem;
  }

  .breadcrumb ol {
    font-size: 0.78rem;
    padding: 0.5rem 0.85rem;
  }

  main > section > h2 {
    padding-left: 0.85rem;
    margin-bottom: 1.25rem;
  }

  main > section > h2::before {
    width: 4px;
  }

  main > section > article {
    padding: 1.15rem 1.1rem;
    border-radius: var(--r-md);
  }

  .stats-list {
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
  }

  .stats-list li {
    padding: 1rem 0.5rem;
  }

  .stat-num {
    font-size: 1.5rem;
  }

  .news-list > li {
    padding: 1rem 1.1rem;
  }

  .news-list > li:hover {
    transform: translateY(-3px);
  }

  .testimonial-list > li {
    padding: 1.5rem 1.1rem 1rem;
  }

  .faq-list dt button {
    padding: 0.85rem 1rem;
    font-size: 0.92rem;
  }

  .faq-list dd {
    font-size: 0.88rem;
  }

  #howto article ol li {
    padding: 0.75rem 0.85rem 0.75rem 3rem;
    font-size: 0.88rem;
  }

  #howto article ol li::before {
    left: 0.7rem;
    width: 26px;
    height: 26px;
    font-size: 0.78rem;
  }

  #contact address {
    padding: 1.1rem;
    gap: 0.6rem;
  }

  #site-footer section[aria-labelledby="footer-legal"] {
    padding: 1.1rem;
  }

  #back-to-top {
    width: 46px;
    height: 46px;
  }

  #back-to-top::before {
    font-size: 1.1rem;
  }
}

@media (max-width: 420px) {
  .logo-text {
    display: none;
  }

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

  .hero-lead {
    font-size: 0.92rem;
  }
}

/* --------------------------------------------------------------------------
   21. 打印样式
   -------------------------------------------------------------------------- */
@media print {
  #site-header,
  #back-to-top,
  .header-actions,
  .hero-actions,
  .search-form,
  #theme-toggle,
  #menu-toggle {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  #hero {
    background: #fff;
    color: #000;
    box-shadow: none;
    border: 1px solid #ccc;
  }

  #hero-title,
  .hero-lead,
  .hero-keywords,
  .hero-visual figcaption {
    color: #000;
  }

  main > section > article,
  .news-list > li,
  .testimonial-list > li {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}

/* --------------------------------------------------------------------------
   22. 动效增强：滚动进入（JS 添加 .js-reveal 时生效）
   -------------------------------------------------------------------------- */
@media (hover: hover) {
  .hero-visual:hover figcaption {
    color: #fff;
  }
}

/* 高对比度模式 */
@media (forced-colors: active) {
  .btn-primary,
  .btn-secondary,
  .search-form button,
  #back-to-top {
    border: 2px solid ButtonText;
  }

  .faq-list dt button::after {
    border: 1px solid ButtonText;
  }
}
```