```css
/* ========== 全局变量与重置 ========== */
:root {
  /* Light scheme */
  --bg-light: #f8fafc;
  --bg-deep-light: #eef2f7;
  --text-primary-light: #1e293b;
  --text-secondary-light: #475569;
  --text-heading-light: #0f172a;
  --card-bg-light: #ffffff;
  --border-light: #e2e8f0;
  --bg-nav-light: rgba(255, 255, 255, 0.85);
  --text-link-light: #1d4ed8;
  --btn-bg-light: #1e3a8a;
  --btn-text-light: #ffffff;
  --footer-bg-light: #1e293b;
  --footer-text-light: #cbd5e1;
  --footer-heading-light: #f8fafc;
  --shadow-light: 0 20px 40px rgba(0, 0, 0, 0.06), 0 8px 20px rgba(0, 0, 0, 0.04);
  --hero-start: #0f172a;
  --hero-end: #1e3a8a;
  --hero-accent: #3b82f6;
  --badge-bg-light: #dbeafe;
  --badge-text-light: #1e40af;
  --faq-border-light: #bfdbfe;

  /* Dark scheme */
  --bg-dark: #0b1120;
  --bg-deep-dark: #020617;
  --text-primary-dark: #e2e8f0;
  --text-secondary-dark: #94a3b8;
  --text-heading-dark: #f1f5f9;
  --card-bg-dark: #1e293b;
  --border-dark: #334155;
  --bg-nav-dark: rgba(15, 23, 42, 0.9);
  --text-link-dark: #93c5fd;
  --btn-bg-dark: #3b82f6;
  --btn-text-dark: #ffffff;
  --footer-bg-dark: #020617;
  --footer-text-dark: #94a3b8;
  --footer-heading-dark: #f1f5f9;
  --shadow-dark: 0 20px 40px rgba(0, 0, 0, 0.4), 0 8px 20px rgba(0, 0, 0, 0.3);
  --hero-start-dark: #020617;
  --hero-end-dark: #1e3a8a;
  --badge-bg-dark: #1e293b;
  --badge-text-dark: #93c5fd;
  --faq-border-dark: #3b82f6;

  --radius-card: 24px;
  --radius-btn: 50px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== 基础重置 ========== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  background: var(--bg-light);
  color: var(--text-primary-light);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.75;
  letter-spacing: 0.01em;
  transition: background-color 0.4s ease, color 0.4s ease;
  min-height: 100vh;
  overflow-x: hidden;
}

body.dark-mode {
  background: var(--bg-dark);
  color: var(--text-primary-dark);
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 10px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #3b82f6, #1e3a8a);
  border-radius: 20px;
  border: 2px solid transparent;
  background-clip: padding-box;
}
body.dark-mode ::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #60a5fa, #3b82f6);
  border: 2px solid transparent;
  background-clip: padding-box;
}

/* ========== 排版 ========== */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading-light);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.02em;
  transition: color 0.4s ease;
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4,
body.dark-mode h5,
body.dark-mode h6 {
  color: var(--text-heading-dark);
}

h1 {
  font-size: clamp(2rem, 4.5vw, 3.2rem);
  margin-bottom: 1.2rem;
  font-weight: 900;
}

h2 {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  margin: 2.5rem 0 1.2rem;
  position: relative;
  padding-left: 1.2rem;
  border-left: 6px solid transparent;
  border-image: linear-gradient(180deg, #3b82f6, #1e3a8a) 1;
  border-image-slice: 1;
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  margin: 1.5rem 0 0.75rem;
  font-weight: 700;
}

h4 {
  font-size: 1.1rem;
  margin: 1.2rem 0 0.5rem;
  font-weight: 600;
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary-light);
  transition: color 0.4s ease;
}

body.dark-mode p {
  color: var(--text-secondary-dark);
}

a {
  color: var(--text-link-light);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease, text-decoration 0.2s ease;
  position: relative;
}

body.dark-mode a {
  color: var(--text-link-dark);
}

a:hover {
  text-decoration: underline;
  color: #2563eb;
}

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

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

/* ========== 容器布局 ========== */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 48px);
}

/* ========== 导航栏 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-nav-light);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid rgba(148, 163, 184, 0.15);
  transition: background-color 0.4s ease, border-color 0.4s ease;
}

body.dark-mode .site-header {
  background: var(--bg-nav-dark);
  border-bottom: 1px solid rgba(148, 163, 184, 0.1);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 16px 0;
  gap: 12px;
}

.logo {
  font-size: clamp(1.3rem, 2vw, 1.8rem);
  font-weight: 900;
  background: linear-gradient(135deg, #3b82f6, #8b5cf6);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  letter-spacing: -0.03em;
  white-space: nowrap;
}

body.dark-mode .logo {
  background: linear-gradient(135deg, #60a5fa, #a78bfa);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  gap: clamp(16px, 3vw, 32px);
  flex-wrap: wrap;
  align-items: center;
}

.nav-links a {
  font-weight: 600;
  color: var(--text-primary-light);
  font-size: 0.95rem;
  position: relative;
  padding: 4px 0;
}

body.dark-mode .nav-links a {
  color: var(--text-primary-dark);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  transition: width 0.3s ease;
}

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

.nav-links a:hover {
  text-decoration: none;
}

.nav-right {
  display: flex;
  gap: 10px;
  align-items: center;
}

/* 搜索框 */
.search-box {
  display: flex;
  background: var(--card-bg-light);
  border-radius: var(--radius-btn);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
  transition: all 0.3s ease;
}

body.dark-mode .search-box {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
}

.search-box:focus-within {
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.search-box input {
  border: none;
  padding: 8px 16px;
  background: transparent;
  color: var(--text-primary-light);
  width: clamp(100px, 12vw, 180px);
  outline: none;
  font-size: 0.9rem;
}

body.dark-mode .search-box input {
  color: var(--text-primary-dark);
}

.search-box input::placeholder {
  color: var(--text-secondary-light);
  opacity: 0.7;
}

body.dark-mode .search-box input::placeholder {
  color: var(--text-secondary-dark);
}

.search-box button {
  background: linear-gradient(135deg, #3b82f6, #1e3a8a);
  color: white;
  border: none;
  padding: 8px 16px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.search-box button:hover {
  opacity: 0.9;
}

/* 暗色切换按钮 */
.dark-toggle {
  background: transparent;
  border: 1px solid var(--border-light);
  padding: 8px 16px;
  border-radius: var(--radius-btn);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-primary-light);
  transition: all 0.3s ease;
  white-space: nowrap;
}

body.dark-mode .dark-toggle {
  color: var(--text-primary-dark);
  border-color: var(--border-dark);
}

.dark-toggle:hover {
  border-color: #3b82f6;
  box-shadow: 0 0 12px rgba(59, 130, 246, 0.2);
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--text-heading-light);
  line-height: 1;
  padding: 4px;
}

body.dark-mode .menu-toggle {
  color: var(--text-heading-dark);
}

/* ========== 面包屑 ========== */
.breadcrumb {
  padding: 1rem 0;
  font-size: 0.9rem;
  color: var(--text-secondary-light);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

body.dark-mode .breadcrumb {
  color: var(--text-secondary-dark);
}

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

body.dark-mode .breadcrumb a {
  color: var(--text-link-dark);
}

/* ========== Hero Banner ========== */
.hero {
  background: linear-gradient(135deg, var(--hero-start) 0%, var(--hero-end) 100%);
  color: #f1f5f9;
  padding: clamp(3rem, 8vw, 6rem) 0;
  position: relative;
  overflow: hidden;
}

body.dark-mode .hero {
  background: linear-gradient(135deg, var(--hero-start-dark) 0%, var(--hero-end-dark) 100%);
}

/* 装饰光斑 */
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60vw;
  height: 60vw;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 40vw;
  height: 40vw;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

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

.hero h1 {
  color: #ffffff;
  font-size: clamp(1.8rem, 4vw, 3rem);
  max-width: 900px;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

.hero p {
  color: #e2e8f0;
  font-size: clamp(1rem, 1.5vw, 1.2rem);
  max-width: 800px;
  line-height: 1.8;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.15);
}

.hero .btn-primary {
  background: rgba(255, 255, 255, 0.15);
  color: #ffffff;
  padding: 14px 32px;
  border-radius: var(--radius-btn);
  font-weight: 700;
  border: 1px solid rgba(255, 255, 255, 0.3);
  cursor: pointer;
  display: inline-block;
  margin-top: 24px;
  font-size: 1rem;
  backdrop-filter: blur(10px);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  letter-spacing: 0.02em;
}

.hero .btn-primary:hover {
  background: #3b82f6;
  border-color: #3b82f6;
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 20px 40px rgba(59, 130, 246, 0.4);
}

/* ========== 卡片网格 ========== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  margin: 2rem 0;
}

.card {
  background: var(--card-bg-light);
  border-radius: var(--radius-card);
  padding: 28px;
  box-shadow: var(--shadow-light);
  border: 1px solid var(--border-light);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

body.dark-mode .card {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-dark);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #3b82f6, #8b5cf6);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.card:hover::before {
  opacity: 1;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.1);
}

body.dark-mode .card:hover {
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.5);
}

.card h3 {
  margin-top: 0;
  font-size: 1.3rem;
}

.card p {
  margin-bottom: 0;
  font-size: 0.95rem;
}

/* ========== 文章列表 ========== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.article-item {
  border-bottom: 1px solid var(--border-light);
  padding: 20px 0;
  transition: all 0.3s ease;
  border-radius: 12px;
  padding-left: 16px;
  padding-right: 16px;
  margin: 0 -16px;
}

body.dark-mode .article-item {
  border-color: var(--border-dark);
}

.article-item:hover {
  background: rgba(59, 130, 246, 0.03);
  border-radius: 16px;
}

body.dark-mode .article-item:hover {
  background: rgba(59, 130, 246, 0.08);
}

.article-item h3 {
  margin: 0 0 8px 0;
  font-size: 1.15rem;
  transition: color 0.2s ease;
}

.article-item:hover h3 {
  color: #3b82f6;
}

.article-meta {
  font-size: 0.85rem;
  color: var(--text-secondary-light);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

body.dark-mode .article-meta {
  color: var(--text-secondary-dark);
}

.article-item p {
  margin-bottom: 0;
  font-size: 0.95rem;
}

/* ========== FAQ 样式 ========== */
.faq-item {
  margin-bottom: 16px;
  border-radius: 16px;
  overflow: hidden;
}

.faq-question {
  background: var(--card-bg-light);
  border: 1px solid var(--border-light);
  padding: 18px 24px;
  border-radius: 16px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
  font-size: 1rem;
  color: var(--text-heading-light);
}

body.dark-mode .faq-question {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
  color: var(--text-heading-dark);
}

.faq-question:hover {
  border-color: #3b82f6;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.08);
}

.faq-question span {
  font-size: 1.5rem;
  transition: transform 0.3s ease;
  color: #3b82f6;
  line-height: 1;
}

.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  border-left: 3px solid transparent;
  margin-left: 12px;
  color: var(--text-secondary-light);
  font-size: 0.95rem;
  line-height: 1.8;
}

body.dark-mode .faq-answer {
  color: var(--text-secondary-dark);
}

.faq-item.active .faq-question {
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
  border-color: #3b82f6;
}

.faq-item.active .faq-answer {
  padding: 16px 24px;
  max-height: 500px;
  border-left-color: #3b82f6;
  background: rgba(59, 130, 246, 0.02);
}

body.dark-mode .faq-item.active .faq-answer {
  background: rgba(59, 130, 246, 0.05);
}

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

/* ========== HowTo 区块 ========== */
#howto .container > div {
  background: var(--card-bg-light);
  padding: clamp(20px, 4vw, 40px);
  border-radius: var(--radius-card);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-light);
  transition: all 0.3s ease;
}

body.dark-mode #howto .container > div {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-dark);
}

#howto h3 {
  color: #3b82f6;
  border-bottom: 2px solid #3b82f6;
  padding-bottom: 6px;
  display: inline-block;
  margin-top: 24px;
}

#howto h3:first-of-type {
  margin-top: 0;
}

/* ========== 联系区块 ========== */
#contact {
  margin: 40px 0;
}

#contact > div {
  display: flex;
  flex-wrap: wrap;
  gap: clamp(24px, 4vw, 48px);
}

#contact > div > div {
  flex: 1;
  min-width: 250px;
  background: var(--card-bg-light);
  border-radius: var(--radius-card);
  padding: 28px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-light);
  transition: all 0.3s ease;
}

body.dark-mode #contact > div > div {
  background: var(--card-bg-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-dark);
}

#contact h4 {
  color: #3b82f6;
  margin-bottom: 16px;
}

#contact p {
  font-size: 0.95rem;
  line-height: 1.9;
}

/* ========== 页脚 ========== */
.site-footer {
  background: var(--footer-bg-light);
  color: var(--footer-text-light);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  position: relative;
}

body.dark-mode .site-footer {
  background: var(--footer-bg-dark);
  color: var(--footer-text-dark);
}

.site-footer h4 {
  color: var(--footer-heading-light);
  margin-bottom: 16px;
  font-size: 1.1rem;
}

body.dark-mode .site-footer h4 {
  color: var(--footer-heading-dark);
}

.site-footer a {
  color: #93c5fd;
  transition: color 0.2s ease;
}

body.dark-mode .site-footer a {
  color: #bfdbfe;
}

.site-footer a:hover {
  color: #60a5fa;
  text-decoration: none;
}

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

.copyright {
  border-top: 1px solid rgba(148, 163, 184, 0.2);
  margin-top: 24px;
  padding-top: 24px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--footer-text-light);
}

body.dark-mode .copyright {
  color: var(--footer-text-dark);
}

/* ========== 徽章样式 ========== */
.badge {
  background: var(--badge-bg-light);
  color: var(--badge-text-light);
  padding: 6px 14px;
  border-radius: 30px;
  font-size: 0.8rem;
  font-weight: 600;
  display: inline-block;
}

body.dark-mode .badge {
  background: var(--badge-bg-dark);
  color: var(--badge-text-dark);
}

/* ========== 滚动动画 ========== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 动画延迟 */
.delay-1 { transition-delay: 0.1s; }
.delay-2 { transition-delay: 0.2s; }
.delay-3 { transition-delay: 0.3s; }
.delay-4 { transition-delay: 0.4s; }
.delay-5 { transition-delay: 0.5s; }

/* ========== 返回顶部按钮 ========== */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: linear-gradient(135deg, #3b82f6, #1e3a8a);
  color: white;
  border: none;
  padding: 12px 20px;
  border-radius: var(--radius-btn);
  font-weight: 700;
  box-shadow: 0 8px 24px rgba(59, 130, 246, 0.3);
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.3s ease;
  z-index: 999;
  display: flex;
  align-items: center;
  gap: 8px;
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(59, 130, 246, 0.4);
}

body.dark-mode .back-to-top {
  background: linear-gradient(135deg, #60a5fa, #3b82f6);
}

/* ========== 响应式设计 ========== */
@media (max-width: 1024px) {
  .nav-wrap {
    gap: 8px;
  }
  
  .nav-links {
    gap: 16px;
  }
  
  .search-box input {
    width: 120px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 12px;
    padding: 20px 0;
    border-top: 1px solid var(--border-light);
    background: var(--bg-nav-light);
    backdrop-filter: blur(20px);
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  }
  
  body.dark-mode .nav-links {
    background: var(--bg-nav-dark);
    border-top-color: var(--border-dark);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .menu-toggle {
    display: block;
    order: 3;
  }
  
  .nav-wrap {
    position: relative;
  }
  
  .nav-right {
    order: 2;
    margin-left: auto;
  }
  
  .logo {
    order: 1;
  }
  
  .search-box input {
    width: 100px;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .grid {
    grid-template-columns: 1fr;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .back-to-top {
    bottom: 20px;
    right: 20px;
    padding: 10px 16px;
  }
}

@media (max-width: 480px) {
  .nav-right {
    gap: 6px;
  }
  
  .search-box input {
    width: 80px;
    padding: 6px 10px;
  }
  
  .search-box button {
    padding: 6px 10px;
  }
  
  .dark-toggle {
    padding: 6px 12px;
    font-size: 0.8rem;
  }
  
  .hero {
    padding: 2.5rem 0;
  }
  
  .hero h1 {
    font-size: 1.5rem;
  }
  
  .card {
    padding: 20px;
  }
  
  .faq-question {
    padding: 14px 16px;
    font-size: 0.95rem;
  }
  
  .faq-answer {
    padding: 0 16px;
  }
  
  .faq-item.active .faq-answer {
    padding: 14px 16px;
  }
  
  .article-item {
    padding: 16px 8px;
    margin: 0 -8px;
  }
}

/* 无障碍支持：减少动画 */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* 打印样式 */
@media print {
  .site-header,
  .hero,
  .back-to-top,
  .search-box,
  .dark-toggle,
  .menu-toggle {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .container {
    max-width: 100%;
  }
}

```