```css
:root {
  --bg-light: #ffffff;
  --bg-dark: #0b111a;
  --text-primary-light: #1F2937;
  --text-secondary-light: #334155;
  --heading-light: #17202A;
  --card-bg-light: #f8fafc;
  --border-light: #e2e8f0;
  --bg-footer-light: #1e293b;
  --text-footer-light: #f1f5f9;
  --accent: #2563eb;
  --accent-dark: #1e40af;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.3);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
  --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e3a8a 50%, #2563eb 100%);
  --gradient-card: linear-gradient(145deg, #ffffff 0%, #f0f4ff 100%);
}

[data-theme="dark"] {
  --bg-light: #0b111a;
  --bg-dark: #0b111a;
  --text-primary-light: #E2E8F0;
  --text-secondary-light: #CBD5E1;
  --heading-light: #FFFFFF;
  --card-bg-light: #1e293b;
  --border-light: #334155;
  --bg-footer-light: #0f172a;
  --text-footer-light: #E2E8F0;
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(148, 163, 184, 0.2);
  --gradient-card: linear-gradient(145deg, #1e293b 0%, #0f172a 100%);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg-light);
  color: var(--text-primary-light);
  line-height: 1.7;
  transition: background 0.4s ease, color 0.3s ease;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5 {
  color: var(--heading-light);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2rem, 5vw, 3rem); margin-bottom: 0.8rem; }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.2rem); margin: 2.5rem 0 1.2rem; border-left: 5px solid var(--accent); padding-left: 1.2rem; }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); margin: 1.5rem 0 0.8rem; }
h4 { font-size: 1.1rem; margin: 1.2rem 0 0.5rem; font-weight: 600; }

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

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

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

ul, ol {
  padding-left: 1.5rem;
  margin-bottom: 1.2rem;
}

li {
  margin-bottom: 0.4rem;
  color: var(--text-primary-light);
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 导航栏 ===== */
.navbar {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  padding: 0.8rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: all 0.3s ease;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.04);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
  background: var(--glass-bg);
}

.nav-flex {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--heading-light);
  letter-spacing: -0.03em;
  transition: transform 0.2s ease;
}

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

.logo span {
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 0.3rem;
  align-items: center;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-primary-light);
  font-weight: 500;
  padding: 0.5rem 0.9rem;
  border-radius: 50px;
  transition: all 0.25s ease;
  position: relative;
}

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

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

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

.nav-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.theme-toggle, .mobile-menu-btn {
  background: var(--card-bg-light);
  border: 1px solid var(--border-light);
  color: var(--text-primary-light);
  padding: 0.45rem 1.1rem;
  border-radius: 50px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.theme-toggle:hover, .mobile-menu-btn:hover {
  border-color: var(--accent);
  background: rgba(37, 99, 235, 0.08);
  transform: translateY(-1px);
}

.mobile-menu-btn {
  display: none;
  font-size: 1.3rem;
  padding: 0.3rem 0.8rem;
}

/* ===== Hero 首屏 ===== */
.hero {
  background: var(--gradient-hero);
  color: white;
  padding: 5rem 0;
  position: relative;
  overflow: hidden;
  border-radius: 0 0 30px 30px;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: 10%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-20px) scale(1.05); }
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero h1 {
  color: white;
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  margin-bottom: 1rem;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
  animation: fadeInUp 0.8s ease;
}

.hero p {
  color: rgba(255, 255, 255, 0.9);
  font-size: clamp(1rem, 2vw, 1.2rem);
  max-width: 720px;
  margin-bottom: 2rem;
  text-shadow: 0 1px 10px rgba(0, 0, 0, 0.15);
  animation: fadeInUp 0.8s ease 0.1s backwards;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: white !important;
  padding: 0.9rem 2.5rem;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1.05rem;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.8s ease 0.2s backwards;
}

.btn::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s ease;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 25px rgba(37, 99, 235, 0.4);
  text-decoration: none;
  color: white !important;
}

.btn:hover::after {
  left: 100%;
}

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

.card {
  background: var(--gradient-card);
  border: 1px solid var(--border-light);
  border-radius: 20px;
  padding: 2rem;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), #7c3aed);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(37, 99, 235, 0.3);
}

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

.card h3 {
  margin-top: 0;
  color: var(--heading-light);
  font-size: 1.3rem;
}

.card p {
  color: var(--text-secondary-light);
  margin-bottom: 0;
}

/* ===== 网格布局 ===== */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

/* ===== 表格样式 ===== */
table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 2rem 0;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

th {
  background: linear-gradient(135deg, var(--accent), var(--accent-dark));
  color: white;
  padding: 14px 16px;
  text-align: left;
  font-weight: 600;
}

td {
  padding: 14px 16px;
  color: var(--text-primary-light);
  border-bottom: 1px solid var(--border-light);
  background: var(--card-bg-light);
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: rgba(37, 99, 235, 0.04);
}

/* ===== 区块与文章列表 ===== */
.article-list {
  display: grid;
  gap: 1.5rem;
}

.article-item {
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 1.5rem;
  transition: all 0.3s ease;
  border-radius: 12px;
  padding: 1.2rem;
  background: transparent;
}

.article-item:hover {
  background: var(--card-bg-light);
  padding-left: 1.5rem;
  border-radius: 12px;
}

.article-item h3 {
  font-size: 1.2rem;
  margin-bottom: 0.4rem;
  transition: color 0.2s ease;
}

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

.article-item .meta {
  color: var(--text-secondary-light);
  font-size: 0.85rem;
  margin-bottom: 0.6rem;
}

.article-item p {
  margin-bottom: 0.5rem;
  color: var(--text-secondary-light);
}

.article-item a {
  font-weight: 600;
  font-size: 0.95rem;
}

/* ===== FAQ 样式 ===== */
.faq-item {
  border: 1px solid var(--border-light);
  border-radius: 16px;
  margin-bottom: 1rem;
  background: var(--card-bg-light);
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: rgba(37, 99, 235, 0.3);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  font-weight: 600;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--heading-light);
  padding: 1.2rem 1.5rem;
  transition: all 0.2s ease;
  user-select: none;
}

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

.faq-question span {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--accent);
}

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

.faq-answer {
  padding: 0 1.5rem 1.2rem;
  color: var(--text-secondary-light);
  line-height: 1.8;
}

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

footer h4 {
  color: white;
  margin-bottom: 1rem;
  font-size: 1.1rem;
}

footer a {
  color: #93c5fd;
  transition: all 0.2s ease;
  line-height: 2;
}

footer a:hover {
  color: white;
}

footer p {
  color: #cbd5e1;
  line-height: 1.8;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2.5rem;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 2rem;
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.9rem;
  color: #94a3b8;
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: white;
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 1.5rem;
  cursor: pointer;
  display: none;
  z-index: 999;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.4);
  transition: all 0.3s ease;
}

.back-to-top.show {
  display: block;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(37, 99, 235, 0.5);
}

/* ===== 区块通用 ===== */
section {
  padding: 1rem 0;
  scroll-margin-top: 80px;
}

/* ===== 高亮与工具类 ===== */
.highlight {
  background: linear-gradient(120deg, rgba(37, 99, 235, 0.1), rgba(124, 58, 237, 0.1));
  padding: 0.2rem 0.6rem;
  border-radius: 8px;
  font-weight: 500;
}

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

.svg-placeholder {
  background: linear-gradient(135deg, #e2e8f0, #f1f5f9);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 180px;
  color: #1e293b;
  font-weight: 500;
  border: 1px dashed var(--border-light);
}

/* ===== 联系区块 ===== */
#contact .grid-2 > div {
  padding: 2rem;
  border-radius: 16px;
  background: var(--card-bg-light);
  border: 1px solid var(--border-light);
}

#contact svg {
  border-radius: 12px;
  overflow: hidden;
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 900px) {
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .grid-3 {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: flex-start;
    margin-top: 1rem;
    padding: 1rem 0;
    border-top: 1px solid var(--border-light);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: 0 0 16px 16px;
  }
  
  .nav-links.active {
    display: flex;
    animation: fadeIn 0.3s ease;
  }
  
  .nav-links a {
    width: 100%;
    padding: 0.7rem 1rem;
    border-radius: 8px;
  }
  
  .nav-links a::after {
    display: none;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  .hero {
    padding: 3.5rem 0;
  }
  
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
}

@media (max-width: 700px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .back-to-top {
    bottom: 1.2rem;
    right: 1.2rem;
    width: 45px;
    height: 45px;
    font-size: 1.3rem;
  }
  
  .container {
    padding: 0 16px;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .faq-question {
    font-size: 1rem;
    padding: 1rem 1.2rem;
  }
  
  .faq-answer {
    padding: 0 1.2rem 1rem;
  }
}

/* ===== 暗色模式适配 ===== */
[data-theme="dark"] .hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #312e81 100%);
}

[data-theme="dark"] .card {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .article-item:hover {
  background: rgba(255, 255, 255, 0.03);
}

[data-theme="dark"] #contact .grid-2 > div {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] svg text {
  fill: #e2e8f0;
}

[data-theme="dark"] .svg-placeholder {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  color: #e2e8f0;
  border-color: #334155;
}

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

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

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--accent), var(--accent-dark));
  border-radius: 10px;
  border: 2px solid var(--bg-light);
}

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

/* ===== 选择文本 ===== */
::selection {
  background: rgba(37, 99, 235, 0.2);
  color: var(--text-primary-light);
}

/* ===== 滚动进入动画 ===== */
@keyframes scrollReveal {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card-grid .card,
.grid-2 > div,
.grid-3 > div,
.article-item,
.faq-item {
  animation: scrollReveal 0.6s ease backwards;
}

.card-grid .card:nth-child(1) { animation-delay: 0.05s; }
.card-grid .card:nth-child(2) { animation-delay: 0.1s; }
.card-grid .card:nth-child(3) { animation-delay: 0.15s; }
.card-grid .card:nth-child(4) { animation-delay: 0.2s; }

/* ===== 加载动画 ===== */
@keyframes shimmer {
  0% { background-position: -1000px 0; }
  100% { background-position: 1000px 0; }
}

/* ===== 打印优化 ===== */
@media print {
  .navbar, .back-to-top, .theme-toggle, .mobile-menu-btn {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .hero {
    background: white;
    color: black;
    padding: 2rem 0;
  }
  
  .hero h1, .hero p {
    color: black;
    text-shadow: none;
  }
  
  a {
    color: black;
    text-decoration: underline;
  }
}

/* ===== 无障碍优化 ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===== 焦点可见性 ===== */
:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===== 暗色模式系统偏好 ===== */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-light: #0b111a;
    --bg-dark: #0b111a;
    --text-primary-light: #E2E8F0;
    --text-secondary-light: #CBD5E1;
    --heading-light: #FFFFFF;
    --card-bg-light: #1e293b;
    --border-light: #334155;
    --bg-footer-light: #0f172a;
    --text-footer-light: #E2E8F0;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(148, 163, 184, 0.2);
  }
}
```