```css
/* ===== 全局重置与变量 ===== */
:root {
  --bg-primary: #f7f9fc;
  --bg-card: #ffffff;
  --bg-nav: #ffffff;
  --bg-footer: #0f172a;
  --text-primary: #1f2937;
  --text-secondary: #2d3a4f;
  --text-heading: #111827;
  --text-accent: #1e3a8a;
  --text-on-dark: #f1f5f9;
  --text-link: #1d4ed8;
  --border-light: #e2e8f0;
  --brand: #1a365d;
  --brand-light: #2c5282;
  --shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
  --radius: 20px;
  --transition: 0.25s ease;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.3);
  --hero-grad-1: #dce6f5;
  --hero-grad-2: #edf2fa;
  --card-hover-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  --btn-gradient: linear-gradient(135deg, #1a365d, #2c5282);
  --btn-hover-gradient: linear-gradient(135deg, #2c5282, #1a365d);
}

html[data-theme="dark"] {
  --bg-primary: #0b1120;
  --bg-card: #152238;
  --bg-nav: #0f172a;
  --bg-footer: #020617;
  --text-primary: #e2e8f0;
  --text-secondary: #cbd5e1;
  --text-heading: #ffffff;
  --text-accent: #93c5fd;
  --text-on-dark: #f8fafc;
  --text-link: #7aa7ff;
  --border-light: #1e2a44;
  --brand: #1e3a8a;
  --glass-bg: rgba(15, 23, 42, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --hero-grad-1: #14283f;
  --hero-grad-2: #0f1f33;
  --shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
  --card-hover-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
}

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

/* ===== 标题与文本 ===== */
h1, h2, h3, h4 {
  color: var(--text-heading);
  font-weight: 650;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

html[data-theme="dark"] h1 {
  background: linear-gradient(135deg, #93c5fd, #ffffff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 2rem 0 1rem;
  border-left: 6px solid var(--brand);
  padding-left: 1rem;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -5px;
  width: 40px;
  height: 3px;
  background: var(--brand-light);
  border-radius: 3px;
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  margin: 1.8rem 0 0.8rem;
  position: relative;
}

h4 {
  font-size: 1.1rem;
  margin: 1.2rem 0 0.5rem;
  color: var(--text-secondary);
  font-weight: 600;
}

p {
  margin-bottom: 1.2rem;
  color: var(--text-primary);
  line-height: 1.8;
}

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

a:hover {
  text-decoration: underline;
  color: var(--brand);
}

ul, ol {
  padding-left: 1.8rem;
  margin-bottom: 1.2rem;
}

li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

/* ===== 容器与布局 ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

/* ===== 毛玻璃效果 ===== */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
}

/* ===== 导航栏 ===== */
.navbar {
  background: var(--bg-nav);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.02);
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border-light);
  transition: background 0.3s;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.85);
}

html[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.85);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 2rem;
  flex-wrap: wrap;
  max-width: 1400px;
  margin: 0 auto;
}

.logo a {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text-heading);
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  transition: transform 0.3s;
}

.logo a:hover {
  transform: scale(1.02);
  text-decoration: none;
}

.logo span {
  background: var(--brand);
  color: white;
  padding: 4px 12px;
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 600;
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-primary);
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
  text-decoration: none;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand);
  transition: width 0.3s;
}

.nav-links a:hover {
  color: var(--text-link);
  text-decoration: none;
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-primary);
  border: 1px solid var(--border-light);
  border-radius: 40px;
  padding: 0.2rem 0.8rem;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.search-box:focus-within {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.1);
}

.search-box input {
  border: none;
  background: transparent;
  padding: 0.5rem;
  color: var(--text-primary);
  width: 150px;
  outline: none;
  font-size: 0.9rem;
}

.search-box button {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-primary);
  transition: transform 0.2s;
}

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

.icon-btn {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
  margin-left: 0.5rem;
  transition: transform 0.2s, opacity 0.2s;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
}

.icon-btn:hover {
  transform: scale(1.1);
  background: rgba(0, 0, 0, 0.05);
}

html[data-theme="dark"] .icon-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

/* ===== 卡片 ===== */
.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-light);
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--brand), var(--brand-light), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--card-hover-shadow);
  border-color: var(--brand-light);
}

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

/* ===== 徽章 ===== */
.badge {
  background: var(--brand-light);
  color: white;
  padding: 0.2rem 1rem;
  border-radius: 30px;
  font-size: 0.85rem;
  display: inline-block;
  font-weight: 500;
}

/* ===== Hero区域 ===== */
.hero {
  background: linear-gradient(145deg, var(--hero-grad-1), var(--hero-grad-2));
  padding: 3rem 2rem;
  border-radius: 30px;
  margin: 2rem 0;
  border: 1px solid var(--border-light);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1), transparent 70%);
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(20px, -20px); }
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero p {
  font-size: 1.15rem;
  max-width: 800px;
  margin: 0 auto 1.5rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.btn-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
  justify-content: center;
}

.btn {
  background: var(--btn-gradient);
  color: white;
  padding: 0.7rem 1.8rem;
  border-radius: 60px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.3s;
  display: inline-block;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(26, 54, 93, 0.3);
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26, 54, 93, 0.4);
  background: var(--btn-hover-gradient);
  text-decoration: none;
  color: white;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--brand);
  color: var(--brand);
  box-shadow: none;
}

.btn-outline:hover {
  background: var(--brand);
  color: white;
  box-shadow: 0 4px 15px rgba(26, 54, 93, 0.3);
}

/* ===== 数据统计 ===== */
.stats {
  display: flex;
  gap: 2.5rem;
  flex-wrap: wrap;
  justify-content: center;
  padding: 2rem 0;
  margin-top: 2rem;
}

.stat-item {
  text-align: center;
  padding: 1rem 1.5rem;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: 16px;
  border: 1px solid var(--glass-border);
  transition: transform 0.3s;
}

.stat-item:hover {
  transform: scale(1.05);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--brand);
  display: block;
  line-height: 1.2;
}

.stat-item p {
  margin: 0.5rem 0 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* ===== 区块锚点 ===== */
.anchor-offset {
  scroll-margin-top: 80px;
}

/* ===== 文章列表 ===== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.article-item {
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 1.5rem;
  transition: padding-left 0.3s, border-color 0.3s;
  position: relative;
}

.article-item:hover {
  padding-left: 1rem;
  border-color: var(--brand-light);
}

.article-item h3 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  transition: color 0.2s;
}

.article-item:hover h3 {
  color: var(--brand);
}

.meta {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.8rem;
}

.article-item a {
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.article-item a::after {
  content: '→';
  transition: transform 0.2s;
}

.article-item a:hover::after {
  transform: translateX(5px);
}

/* ===== FAQ ===== */
details {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 0.8rem 1.5rem;
  margin-bottom: 0.8rem;
  transition: border-color 0.3s, box-shadow 0.3s;
  overflow: hidden;
}

details:hover {
  border-color: var(--brand-light);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

details[open] {
  border-color: var(--brand);
  box-shadow: 0 4px 12px rgba(26, 54, 93, 0.1);
}

summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text-heading);
  padding: 0.5rem 0;
  list-style: none;
  position: relative;
  padding-right: 1.5rem;
  transition: color 0.2s;
}

summary:hover {
  color: var(--brand);
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: '+';
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.3rem;
  color: var(--brand);
  transition: transform 0.3s;
}

details[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

details p {
  margin-top: 0.8rem;
  color: var(--text-primary);
  padding: 0.5rem 0;
  border-top: 1px solid var(--border-light);
}

/* ===== 表格 ===== */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  background: var(--bg-card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

th, td {
  border: 1px solid var(--border-light);
  padding: 1rem;
  text-align: left;
}

th {
  background: var(--brand);
  color: white;
  font-weight: 600;
}

tr:hover td {
  background: rgba(26, 54, 93, 0.05);
}

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-footer);
  color: var(--text-on-dark);
  padding: 3rem 0 1rem;
  margin-top: 4rem;
  border-radius: 40px 40px 0 0;
  position: relative;
  overflow: hidden;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--brand), var(--brand-light), var(--brand));
}

.footer h4 {
  color: #ffffff;
  font-size: 1.1rem;
  margin-bottom: 1rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.footer h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: var(--brand-light);
}

.footer a {
  color: #cbd5e1;
  text-decoration: none;
  transition: color 0.2s;
}

.footer a:hover {
  color: white;
  text-decoration: underline;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2rem;
  padding: 0 2rem;
}

.footer .copyright {
  border-top: 1px solid #2d3a4f;
  margin-top: 2rem;
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.9rem;
  color: #cbd5e1;
}

/* ===== 返回顶部按钮 ===== */
#backToTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--btn-gradient);
  color: white;
  border: none;
  padding: 12px 16px;
  border-radius: 50%;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  z-index: 99;
  transition: transform 0.3s, box-shadow 0.3s, opacity 0.3s;
  opacity: 0;
  visibility: hidden;
}

#backToTop.visible {
  opacity: 1;
  visibility: visible;
}

#backToTop:hover {
  transform: translateY(-3px) scale(1.1);
  box-shadow: 0 6px 20px rgba(26, 54, 93, 0.4);
}

/* ===== 滚动动画 ===== */
.fade-up {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 图片占位 ===== */
.svg-placeholder {
  width: 100%;
  border-radius: 12px;
  transition: transform 0.3s;
}

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

/* ===== 移动端菜单 ===== */
.menu-toggle {
  display: none;
}

/* ===== 联系与版权 ===== */
#contact p {
  margin-bottom: 0.8rem;
}

#contact .grid-2 .card {
  height: 100%;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .nav-inner {
    padding: 0.7rem 1rem;
  }
  
  .nav-links {
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }
  
  .nav-inner {
    padding: 0.5rem 1rem;
  }
  
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.8rem;
    margin-top: 1rem;
    padding: 1rem 0;
    border-top: 1px solid var(--border-light);
  }
  
  .nav-links.open {
    display: flex;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .search-box input {
    width: 100px;
  }
  
  .search-box {
    max-width: 150px;
  }
  
  .hero {
    padding: 2rem 1rem;
    margin: 1rem 0;
    border-radius: 20px;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .card {
    padding: 1.5rem;
  }
  
  .stats {
    gap: 1.5rem;
  }
  
  .stat-number {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .nav-actions {
    gap: 0.5rem;
  }
  
  .icon-btn {
    margin-left: 0.2rem;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }
  
  .container {
    padding: 0 12px;
  }
  
  .nav-inner {
    padding: 0.5rem;
  }
  
  .logo a {
    font-size: 1.5rem;
  }
  
  .search-box {
    display: none;
  }
  
  .btn-group {
    flex-direction: column;
    width: 100%;
  }
  
  .btn {
    width: 100%;
    text-align: center;
  }
  
  .stats {
    flex-direction: column;
    align-items: center;
    gap: 1rem;
  }
  
  .stat-item {
    width: 100%;
    max-width: 200px;
  }
  
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .hero {
    padding: 1.5rem 0.8rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 0 1rem;
  }
  
  #backToTop {
    bottom: 20px;
    right: 20px;
    padding: 10px 14px;
  }
  
  h1 {
    font-size: 1.6rem;
  }
  
  h2 {
    font-size: 1.3rem;
    padding-left: 0.8rem;
  }
}

/* ===== 打印样式 ===== */
@media print {
  .navbar, .footer, #backToTop, .btn-group {
    display: none;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .container {
    max-width: 100%;
    padding: 0;
  }
}

/* ===== 无障碍优化 ===== */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto;
  }
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
  width: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--brand-light);
  border-radius: 5px;
}

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

/* ===== 选择文本 ===== */
::selection {
  background: var(--brand);
  color: white;
}

/* ===== 加载动画 ===== */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.loading {
  animation: pulse 1.5s ease-in-out infinite;
}

/* ===== 键盘导航 ===== */
a:focus-visible, button:focus-visible {
  outline: 3px solid var(--brand-light);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===== 工具类 ===== */
.text-center {
  text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* ===== 区块标题装饰 ===== */
section {
  position: relative;
}

section > h2 {
  margin-top: 3rem;
}

section:first-of-type > h2 {
  margin-top: 2rem;
}

/* ===== 联系区块样式 ===== */
#contact .grid-2 {
  margin-bottom: 2rem;
}

#contact .card h3 {
  color: var(--brand);
  font-size: 1.3rem;
  margin-bottom: 0.8rem;
}

#contact .card p {
  margin-bottom: 0.6rem;
}

/* ===== 链接图标 ===== */
a[href^="mailto:"]::before {
  content: '📧 ';
}

a[href^="tel:"]::before {
  content: '📞 ';
}

/* ===== 代码块 ===== */
code {
  background: rgba(0, 0, 0, 0.05);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.9em;
}

html[data-theme="dark"] code {
  background: rgba(255, 255, 255, 0.1);
}

/* ===== 引用块 ===== */
blockquote {
  border-left: 4px solid var(--brand);
  padding: 0.5rem 1rem;
  margin: 1rem 0;
  background: var(--bg-card);
  border-radius: 0 8px 8px 0;
  font-style: italic;
}
```