```css
:root {
  --primary-dark: #1A3A5C;
  --primary-text: #17202A;
  --secondary-text: #2C3E50;
  --accent: #B8860B;
  --bg-light: #FFFFFF;
  --bg-soft: #F5F7FA;
  --card-bg: #FFFFFF;
  --border-light: #D5DCE4;
  --footer-bg: #11212E;
  --footer-text: #E2E8F0;
  --nav-bg: rgba(255,255,255,0.95);
  --shadow: 0 4px 12px rgba(0,0,0,0.08);
  --heading-color: #0F1C2E;
  --link-color: #1F4E7A;
  --btn-bg: #1A3A5C;
  --btn-text: #FFFFFF;
  --faq-bg: #F0F4F8;
}
[data-theme="dark"] {
  --primary-dark: #1E293B;
  --primary-text: #E2E8F0;
  --secondary-text: #CBD5E1;
  --accent: #F0B429;
  --bg-light: #0F172A;
  --bg-soft: #1E293B;
  --card-bg: #1A2536;
  --border-light: #334155;
  --footer-bg: #0B131F;
  --footer-text: #E2E8F0;
  --nav-bg: rgba(15,23,42,0.95);
  --heading-color: #F8FAFC;
  --link-color: #7FB0E0;
  --btn-bg: #3B5B7A;
  --btn-text: #FFFFFF;
  --faq-bg: #1E293B;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg-light);
  color: var(--primary-text);
  line-height: 1.7;
  transition: background 0.3s ease, color 0.3s ease;
}
h1, h2, h3, h4 {
  color: var(--heading-color);
  font-weight: 600;
  line-height: 1.3;
}
h1 {
  font-size: 2.2rem;
  margin-bottom: 1rem;
}
h2 {
  font-size: 1.8rem;
  margin: 2rem 0 1rem;
  border-left: 6px solid var(--accent);
  padding-left: 1rem;
}
h3 {
  font-size: 1.4rem;
  margin: 1.5rem 0 0.8rem;
}
h4 {
  font-size: 1.2rem;
  margin: 1rem 0 0.5rem;
  color: var(--secondary-text);
}
p {
  margin-bottom: 1.2rem;
}
a {
  color: var(--link-color);
  text-decoration: none;
  font-weight: 500;
}
a:hover {
  text-decoration: underline;
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow);
  padding: 0.8rem 0;
}
.nav-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--heading-color);
}
.logo span {
  color: var(--accent);
}
.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}
.nav-links a {
  color: var(--heading-color);
  font-weight: 500;
  padding: 0.3rem 0;
}
.nav-links a:hover {
  color: var(--accent);
}
.menu-btn, .search-btn, .theme-btn {
  background: none;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  color: var(--heading-color);
  margin-left: 0.5rem;
}
.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-soft);
  border-radius: 30px;
  padding: 0.3rem 1rem;
}
.search-box input {
  border: none;
  background: transparent;
  padding: 0.5rem;
  width: 180px;
  color: var(--primary-text);
}
.search-box input::placeholder {
  color: var(--secondary-text);
  opacity: 0.8;
}
.search-box button {
  background: var(--btn-bg);
  color: var(--btn-text);
  border: none;
  border-radius: 20px;
  padding: 0.4rem 1rem;
  cursor: pointer;
  font-weight: 500;
}
.banner {
  background: linear-gradient(135deg, #1A3A5C 0%, #2b4f6e 100%);
  color: #fff;
  padding: 3.5rem 0;
  text-align: center;
  margin-bottom: 2rem;
}
.banner h2 {
  color: #FFFFFF;
  border-left: none;
  font-size: 2.5rem;
}
.banner p {
  font-size: 1.3rem;
  color: #E2E8F0;
  max-width: 800px;
  margin: 0.5rem auto 2rem;
}
.banner .btn-group {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.btn {
  background: var(--btn-bg);
  color: var(--btn-text);
  padding: 0.8rem 2rem;
  border-radius: 40px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: 0.2s;
  font-size: 1rem;
}
.btn:hover {
  background: var(--accent);
  color: #fff;
}
.btn-outline {
  background: transparent;
  border: 2px solid #FFFFFF;
  color: #FFFFFF;
}
.btn-outline:hover {
  background: #FFFFFF;
  color: #1A3A5C;
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}
.card {
  background: var(--card-bg);
  padding: 1.8rem;
  border-radius: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-light);
  transition: 0.2s;
}
.card h3 {
  color: var(--heading-color);
  margin-bottom: 0.8rem;
}
.card p {
  color: var(--primary-text);
}
.card .meta {
  color: var(--secondary-text);
  font-size: 0.9rem;
}
.faq-item {
  background: var(--faq-bg);
  border-radius: 12px;
  margin-bottom: 1rem;
  padding: 0;
  border: 1px solid var(--border-light);
}
.faq-q {
  padding: 1rem 1.5rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--heading-color);
}
.faq-a {
  padding: 0 1.5rem 1rem;
  color: var(--primary-text);
}
.faq-a p {
  margin-bottom: 0.5rem;
}
.article-list {
  display: grid;
  gap: 1.5rem;
}
.article-item {
  background: var(--card-bg);
  padding: 1.2rem 1.5rem;
  border-radius: 12px;
  border-left: 6px solid var(--accent);
  box-shadow: var(--shadow);
}
.article-item h3 {
  margin-bottom: 0.3rem;
}
.article-item .date {
  color: var(--secondary-text);
  font-size: 0.9rem;
}
.contact-info {
  background: var(--bg-soft);
  padding: 2rem;
  border-radius: 20px;
}
.contact-info p {
  margin: 0.3rem 0;
}
footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}
footer a {
  color: #9BB8D3;
}
footer .footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}
footer h4 {
  color: #FFFFFF;
}
footer .copyright {
  border-top: 1px solid #334155;
  margin-top: 2rem;
  padding-top: 1.5rem;
  text-align: center;
  color: #CBD5E1;
}
.breadcrumb {
  background: var(--bg-soft);
  padding: 0.5rem 1rem;
  border-radius: 30px;
  display: inline-block;
  font-size: 0.9rem;
  margin: 1rem 0;
}
.howto-step {
  background: var(--card-bg);
  border-left: 4px solid var(--accent);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  border-radius: 8px;
}
.highlight {
  background: rgba(184, 134, 11, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
}
.svg-placeholder {
  background: var(--bg-soft);
  border-radius: 12px;
  padding: 1.5rem;
  text-align: center;
  margin: 1rem 0;
}
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .menu-btn {
    display: block;
  }
  .search-box input {
    width: 120px;
  }
}
.menu-btn {
  display: none;
}
@media (max-width: 768px) {
  .menu-btn {
    display: block;
  }
  .nav-links.mobile-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg-light);
    padding: 1rem;
    box-shadow: var(--shadow);
  }
}
.stats {
  display: flex;
  gap: 2rem;
  justify-content: center;
  margin: 2rem 0;
  flex-wrap: wrap;
}
.stat-num {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
}
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: 0.6s;
}
.reveal.active {
  opacity: 1;
  transform: none;
}
```