```css
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --text-primary: #1f2937;
  --text-secondary: #334155;
  --text-muted: #4b5563;
  --text-link: #1d4ed8;
  --text-heading: #0f172a;
  --border-color: #e2e8f0;
  --nav-bg: rgba(255, 255, 255, 0.95);
  --footer-bg: #0f172a;
  --footer-text: #e2e8f0;
  --footer-link: #94a3b8;
  --btn-bg: #0f172a;
  --btn-text: #ffffff;
  --card-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
  --hover-overlay: rgba(0, 0, 0, 0.03);
  --gradient-hero: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  --gradient-brand: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-accent: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --glass-bg: rgba(255, 255, 255, 0.08);
  --glass-border: rgba(255, 255, 255, 0.15);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-sm: 0.5rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-full: 2rem;
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --text-primary: #e2e8f0;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-link: #60a5fa;
  --text-heading: #f8fafc;
  --border-color: #334155;
  --nav-bg: rgba(15, 23, 42, 0.95);
  --footer-bg: #0b1120;
  --footer-text: #e2e8f0;
  --footer-link: #94a3b8;
  --btn-bg: #3b82f6;
  --btn-text: #ffffff;
  --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
  --hover-overlay: rgba(255, 255, 255, 0.04);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  --gradient-brand: linear-gradient(135deg, #312e81 0%, #4c1d95 100%);
  --gradient-accent: linear-gradient(135deg, #9d174d 0%, #be185d 100%);
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
}

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

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
  min-height: 100vh;
}

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

a:hover {
  color: var(--text-heading);
  text-decoration: none;
}

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

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 20px;
  width: 100%;
}

/* ===== 导航栏 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-color);
  transition: background 0.3s ease, border-color 0.3s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 1rem;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-heading);
  letter-spacing: -0.5px;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.logo:hover {
  transform: scale(1.02);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 0.3rem 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--text-link);
  transition: width var(--transition-normal);
  border-radius: 2px;
}

.nav-links a:hover {
  color: var(--text-heading);
}

.nav-links a:hover::after {
  width: 100%;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  flex-shrink: 0;
}

.icon-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-primary);
  font-size: 1.1rem;
  transition: all var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.icon-btn:hover {
  background: var(--hover-overlay);
  border-color: var(--text-muted);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.mobile-menu-btn {
  display: none;
}

/* 移动菜单 */
.mobile-nav {
  display: none;
  background: var(--bg-primary);
  padding: 0.5rem 1rem 1rem;
  border-top: 1px solid var(--border-color);
  animation: slideDown 0.3s ease;
}

.mobile-nav.open {
  display: block;
}

.mobile-nav a {
  display: block;
  padding: 0.8rem 0.5rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), padding-left var(--transition-fast);
}

.mobile-nav a:hover {
  background: var(--hover-overlay);
  padding-left: 1rem;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 搜索框 */
.search-wrapper {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--border-color);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  position: relative;
}

.search-wrapper:focus-within {
  border-color: var(--text-link);
  box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.1);
}

.search-wrapper input {
  border: none;
  background: transparent;
  padding: 0.4rem 0.6rem;
  font-size: 0.9rem;
  color: var(--text-primary);
  width: 180px;
  outline: none;
}

.search-wrapper input::placeholder {
  color: var(--text-muted);
  opacity: 0.8;
}

.search-wrapper button {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-primary);
  padding: 0.3rem;
  transition: transform var(--transition-fast);
}

.search-wrapper button:hover {
  transform: scale(1.1);
}

/* ===== Hero Banner ===== */
.hero {
  background: var(--gradient-hero);
  color: #f8fafc;
  padding: 4rem 0;
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.3) 0%, transparent 70%);
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.2) 0%, transparent 70%);
  animation: float 6s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(5deg);
  }
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  color: #ffffff;
  line-height: 1.2;
  margin-bottom: 1rem;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

.hero p {
  font-size: 1.1rem;
  color: #cbd5e1;
  max-width: 600px;
  margin-bottom: 2rem;
  line-height: 1.8;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  background: var(--btn-bg);
  color: var(--btn-text);
  padding: 0.8rem 1.8rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  font-size: 0.95rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.btn:hover::after {
  width: 300px;
  height: 300px;
}

.btn-outline {
  background: transparent;
  border: 1px solid #94a3b8;
  color: #e2e8f0;
  box-shadow: none;
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: #e2e8f0;
}

.hero-illustration {
  position: relative;
}

.hero-illustration svg {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-normal);
}

.hero-illustration:hover svg {
  transform: scale(1.02) rotate(1deg);
}

/* ===== 通用卡片 ===== */
.section-title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 2rem;
  border-left: 5px solid var(--text-link);
  padding-left: 1rem;
  position: relative;
  transition: color var(--transition-fast);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.8rem;
  box-shadow: var(--card-shadow);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-fast);
  position: relative;
  overflow: hidden;
  opacity: 0.8;
  transform: translateY(10px);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
  border-color: var(--text-link);
  opacity: 1;
}

.card:hover::before {
  transform: scaleX(1);
}

.card h3 {
  color: var(--text-heading);
  font-size: 1.2rem;
  margin-bottom: 0.6rem;
  font-weight: 600;
  line-height: 1.4;
}

.card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.card-link {
  font-weight: 600;
  display: inline-block;
  position: relative;
  transition: all var(--transition-fast);
}

.card-link:hover {
  transform: translateX(5px);
}

/* ===== 品牌展示 ===== */
.brand-showcase {
  background: var(--bg-secondary);
  padding: 3rem 0;
  border-radius: var(--radius-lg);
  margin: 2.5rem 0;
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
}

.brand-showcase::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at center, rgba(255, 255, 255, 0.05) 0%, transparent 50%);
  animation: rotate 20s linear infinite;
}

@keyframes rotate {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

.brand-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
  text-align: center;
  position: relative;
  z-index: 1;
}

.brand-item {
  padding: 1.5rem;
  border-radius: var(--radius-md);
  transition: transform var(--transition-normal), background var(--transition-fast);
}

.brand-item:hover {
  transform: translateY(-5px);
  background: var(--glass-bg);
}

.brand-item svg {
  width: 64px;
  height: 64px;
  margin: 0 auto 1rem;
  border-radius: var(--radius-md);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  transition: transform var(--transition-normal);
}

.brand-item:hover svg {
  transform: scale(1.1) rotate(-5deg);
}

.brand-item h4 {
  color: var(--text-heading);
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.brand-item p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ===== 文章卡片 ===== */
.article-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.article-meta span {
  background: var(--bg-secondary);
  padding: 0.2rem 0.8rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  border: 1px solid var(--border-color);
}

/* ===== FAQ ===== */
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 0.8rem;
  overflow: hidden;
  transition: all var(--transition-normal);
}

.faq-item:hover {
  border-color: var(--text-link);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.faq-item.open {
  border-color: var(--text-link);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.faq-question {
  padding: 1.2rem 1.5rem;
  font-weight: 600;
  color: var(--text-heading);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

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

.faq-question span {
  font-size: 0.8rem;
  transition: transform var(--transition-normal);
  color: var(--text-muted);
  flex-shrink: 0;
  margin-left: 1rem;
}

.faq-item.open .faq-question span {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.5rem 1.2rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  display: none;
  line-height: 1.8;
  animation: fadeIn 0.3s ease;
}

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

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-5px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Footer ===== */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 4rem 0 2rem;
  margin-top: 4rem;
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-brand);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2.5rem;
}

.footer-grid h4 {
  color: #ffffff;
  font-size: 1.1rem;
  margin-bottom: 1.2rem;
  font-weight: 600;
  position: relative;
  padding-bottom: 0.5rem;
}

.footer-grid h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: var(--text-link);
  border-radius: 2px;
}

.footer-grid a {
  color: var(--footer-link);
  display: block;
  margin-bottom: 0.6rem;
  font-size: 0.9rem;
  transition: all var(--transition-fast);
  padding-left: 0;
}

.footer-grid a:hover {
  color: #ffffff;
  padding-left: 5px;
}

.footer-bottom {
  border-top: 1px solid #1e293b;
  margin-top: 3rem;
  padding-top: 1.5rem;
  text-align: center;
  color: #94a3b8;
  font-size: 0.85rem;
  line-height: 2;
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--btn-bg);
  color: var(--btn-text);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border: none;
  font-size: 1.2rem;
  z-index: 200;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  transition: all var(--transition-normal);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--text-link);
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-grid {
    gap: 2rem;
  }
  
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .card-grid {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  }
}

@media (max-width: 768px) {
  .nav-links,
  .search-wrapper {
    display: none;
  }
  
  .mobile-menu-btn {
    display: inline-flex;
  }
  
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .hero {
    padding: 3rem 0;
    text-align: center;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .hero p {
    font-size: 1rem;
    margin-left: auto;
    margin-right: auto;
  }
  
  .hero-cta {
    justify-content: center;
  }
  
  .hero-illustration {
    max-width: 400px;
    margin: 0 auto;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  
  .brand-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
  }
  
  .brand-item {
    padding: 1rem;
  }
  
  .brand-item svg {
    width: 48px;
    height: 48px;
  }
  
  .footer-grid {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1.5rem;
  }
  
  .back-to-top {
    bottom: 1.5rem;
    right: 1.5rem;
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }
  
  .container {
    padding: 0 15px;
  }
  
  .header-inner {
    height: 56px;
  }
  
  .logo {
    font-size: 1.4rem;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.5rem;
  }
  
  .hero p {
    font-size: 0.95rem;
  }
  
  .hero-cta {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    text-align: center;
  }
  
  .card {
    padding: 1.2rem;
  }
  
  .faq-question {
    padding: 1rem;
    font-size: 0.95rem;
  }
  
  .faq-answer {
    padding: 0 1rem 1rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }
  
  .article-meta {
    flex-direction: column;
    gap: 0.3rem;
  }
}

/* 滚动动画增强 */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* 自定义滚动条 */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 5px;
  border: 2px solid var(--bg-secondary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-link);
}

/* 选中文本样式 */
::selection {
  background: var(--text-link);
  color: #ffffff;
}

/* 焦点样式 */
:focus-visible {
  outline: 3px solid var(--text-link);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 打印样式 */
@media print {
  .site-header,
  .mobile-nav,
  .back-to-top,
  .hero-cta,
  .footer-bottom {
    display: none !important;
  }
  
  body {
    background: #ffffff;
    color: #000000;
  }
  
  .card {
    box-shadow: none;
    border: 1px solid #ddd;
  }
}
```