```css
/* ===== CSS Reset & Variables ===== */
:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1a1a2e;
  --accent: #4a6cf7;
  --border: #e2e8f0;
  --nav-bg: rgba(255, 255, 255, 0.85);
  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-border: rgba(255, 255, 255, 0.3);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
  --gradient-main: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-hover: linear-gradient(135deg, #5a6fd6 0%, #6b3fa0 100%);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.6s cubic-bezier(0.25, 0.8, 0.25, 1);
}

[data-theme="dark"] {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #e2e8f0;
  --accent: #818cf8;
  --border: #334155;
  --nav-bg: rgba(30, 41, 59, 0.85);
  --glass-bg: rgba(30, 41, 59, 0.6);
  --glass-border: rgba(148, 163, 184, 0.2);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 20px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

a {
  color: inherit;
  text-decoration: none;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.1rem; }

p {
  color: var(--text);
  opacity: 0.85;
}

/* ===== Navigation Bar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background 0.3s ease, border-color 0.3s ease;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 20px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.5px;
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

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

.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav-links a {
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  position: relative;
  padding: 4px 0;
  transition: color 0.3s ease;
}

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

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

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

.theme-toggle {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 20px;
  padding: 6px 14px;
  cursor: pointer;
  font-size: 1.1rem;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.theme-toggle:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  transform: rotate(15deg);
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 6px 12px;
  gap: 8px;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.search-box:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.1);
}

.search-box input {
  border: none;
  background: transparent;
  color: var(--text);
  outline: none;
  width: 140px;
  font-size: 0.9rem;
  transition: width 0.3s ease;
}

.search-box input::placeholder {
  color: var(--text);
  opacity: 0.5;
}

.search-box button {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--accent);
  font-size: 1rem;
  transition: transform 0.2s ease;
  padding: 0;
}

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

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px;
  transition: opacity 0.3s ease;
}

/* ===== Mobile Navigation ===== */
@media (max-width: 768px) {
  .nav-inner {
    height: 56px;
    gap: 12px;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 24px;
    gap: 20px;
    box-shadow: var(--shadow-md);
    border-bottom: 1px solid var(--border);
    animation: slideDown 0.3s ease;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links a {
    font-size: 1.1rem;
    padding: 8px 0;
  }

  .menu-toggle {
    display: block;
  }

  .search-box {
    display: none;
  }

  .theme-toggle {
    padding: 4px 10px;
    font-size: 1rem;
  }
}

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

/* ===== Back to Top Button ===== */
.to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: var(--accent);
  color: #fff;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border: none;
  font-size: 1.2rem;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
  box-shadow: var(--shadow-md);
}

.to-top.show {
  opacity: 1;
  visibility: visible;
}

.to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

/* ===== Banner Carousel ===== */
.banner {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-xl);
  margin-top: 24px;
  background: var(--gradient-main);
  color: #fff;
  min-height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
}

.banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: rgba(255, 255, 255, 0.1);
  transform: rotate(45deg);
  animation: bannerShine 8s ease infinite;
}

@keyframes bannerShine {
  0%, 100% { transform: rotate(45deg) translateX(0); }
  50% { transform: rotate(45deg) translateX(30%); }
}

.banner-item {
  display: none;
  text-align: center;
  padding: 48px 24px;
  position: relative;
  z-index: 1;
  animation: fadeIn 0.8s ease;
}

.banner-item.active {
  display: block;
}

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

.banner h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 16px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.banner p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  max-width: 600px;
  margin: 0 auto;
  opacity: 0.9;
  text-shadow: 0 1px 5px rgba(0, 0, 0, 0.2);
}

.banner-btn {
  background: #fff;
  color: #333;
  border: none;
  padding: 12px 32px;
  border-radius: 30px;
  margin-top: 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.banner-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

/* ===== Section Titles ===== */
.section-title {
  font-size: clamp(1.8rem, 3vw, 2.2rem);
  margin: 60px 0 32px;
  text-align: center;
  color: var(--accent);
  position: relative;
  padding-bottom: 16px;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--gradient-main);
  border-radius: 3px;
}

/* ===== Grid Layout ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

/* ===== Cards ===== */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-main);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

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

.card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  transition: color 0.3s ease;
}

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

.card p {
  color: var(--text);
  opacity: 0.85;
  line-height: 1.6;
}

.svg-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  transition: transform 0.3s ease;
}

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

/* ===== FAQ ===== */
.faq-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  padding: 0 20px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}

.faq-q {
  padding: 18px 0;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: color 0.3s ease;
}

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

.faq-a {
  max-height: 0;
  padding: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  color: var(--text);
  opacity: 0.85;
  line-height: 1.6;
}

.faq-item.open .faq-a {
  max-height: 400px;
  padding-bottom: 18px;
}

.faq-item.open .faq-q::after {
  content: "−";
  color: var(--accent);
}

.faq-q::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--accent);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-q::after {
  transform: rotate(180deg);
}

/* ===== Article Cards ===== */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--card);
  border-radius: var(--radius-md);
  padding: 24px;
  border: 1px solid var(--border);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.article-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--gradient-main);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s ease;
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.article-card:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

.article-card .date {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 500;
}

.article-card h4 {
  margin: 12px 0;
  font-size: 1.1rem;
  transition: color 0.3s ease;
}

.article-card:hover h4 {
  color: var(--accent);
}

.article-card .summary {
  color: var(--text);
  opacity: 0.8;
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.article-card a {
  color: var(--accent);
  font-weight: 500;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.article-card a:hover {
  gap: 8px;
}

/* ===== Stats Section ===== */
.stats {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  background: var(--card);
  border-radius: var(--radius-xl);
  padding: 40px 32px;
  margin: 48px 0;
  border: 1px solid var(--border);
  gap: 24px;
}

.stat-item {
  text-align: center;
  flex: 1;
  min-width: 150px;
}

.stat-num {
  font-size: clamp(2rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--accent);
  display: block;
  margin-bottom: 4px;
}

.stat-item p {
  font-size: 0.95rem;
  color: var(--text);
  opacity: 0.7;
}

/* ===== Footer ===== */
footer {
  background: var(--card);
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 48px 0 24px;
  transition: background 0.3s ease;
}

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

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

.footer-grid a {
  display: block;
  color: var(--text);
  text-decoration: none;
  opacity: 0.8;
  margin: 8px 0;
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

.footer-grid a:hover {
  opacity: 1;
  color: var(--accent);
  padding-left: 4px;
}

.copyright {
  text-align: center;
  margin-top: 40px;
  border-top: 1px solid var(--border);
  padding-top: 24px;
  font-size: 0.9rem;
  color: var(--text);
  opacity: 0.8;
  line-height: 1.8;
}

/* ===== Scroll Reveal Animation ===== */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* ===== Anchor Offset ===== */
.anchor-offset {
  scroll-margin-top: 80px;
}

/* ===== HowTo Section ===== */
#howto .card {
  max-width: 800px;
  margin: 0 auto;
}

#howto ol {
  margin-left: 24px;
  margin-top: 12px;
  margin-bottom: 16px;
}

#howto li {
  margin-bottom: 8px;
  line-height: 1.6;
}

#howto p {
  margin-bottom: 12px;
}

#howto strong {
  color: var(--accent);
}

/* ===== Contact Section ===== */
#contact .card {
  text-align: center;
}

#contact .card h3 {
  margin-bottom: 8px;
}

#contact .card p {
  margin-bottom: 16px;
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
  .container {
    padding: 0 16px;
  }

  .grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
  }
}

@media (max-width: 768px) {
  .section-title {
    margin: 48px 0 24px;
  }

  .banner {
    min-height: 200px;
    margin-top: 16px;
  }

  .banner-item {
    padding: 32px 16px;
  }

  .banner h2 {
    font-size: 1.5rem;
  }

  .banner p {
    font-size: 0.95rem;
  }

  .stats {
    padding: 24px 16px;
    gap: 16px;
  }

  .stat-num {
    font-size: 1.8rem;
  }

  .footer-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 24px;
  }

  .to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
}

@media (max-width: 480px) {
  .grid {
    grid-template-columns: 1fr;
  }

  .article-list {
    grid-template-columns: 1fr;
  }

  .banner h2 {
    font-size: 1.2rem;
  }

  .banner p {
    font-size: 0.85rem;
  }

  .card {
    padding: 20px;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .stats {
    flex-direction: column;
    align-items: center;
  }

  .stat-item {
    min-width: 100%;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
}

/* ===== Dark Mode Specific Adjustments ===== */
[data-theme="dark"] .card {
  background: var(--card);
  border-color: var(--border);
}

[data-theme="dark"] .card:hover {
  border-color: var(--accent);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .banner {
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .search-box input {
  color: var(--text);
}

[data-theme="dark"] .search-box input::placeholder {
  color: var(--text);
  opacity: 0.5;
}

[data-theme="dark"] .navbar {
  background: var(--nav-bg);
  border-bottom-color: var(--border);
}

/* ===== Glass Morphism Effect ===== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all 0.3s ease;
}

.glass-card:hover {
  background: var(--card);
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

/* ===== Custom Scrollbar ===== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--accent);
  border-radius: 5px;
  transition: all 0.3s ease;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
  opacity: 0.8;
}

/* ===== Selection Color ===== */
::selection {
  background: var(--accent);
  color: #fff;
}

/* ===== Focus States ===== */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ===== Button Styles ===== */
button {
  font-family: inherit;
}

button:active {
  transform: scale(0.98);
}

/* ===== Link Styles ===== */
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===== Print Styles ===== */
@media print {
  .navbar,
  .to-top,
  .banner-btn,
  .theme-toggle,
  .menu-toggle,
  .search-box {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .card,
  .article-card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }
}
```