:root {
  --primary: #1a73e8;
  --primary-dark: #1557b0;
  --primary-light: #4a9af5;
  --accent: #00c9a7;
  --accent-dark: #00a88b;
  --bg: #f5f7fa;
  --bg-card: #ffffff;
  --bg-header: rgba(255, 255, 255, 0.72);
  --bg-nav: rgba(255, 255, 255, 0.6);
  --text: #1a1a2e;
  --text-secondary: #5a5a7a;
  --text-muted: #8a8aa0;
  --border: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --shadow-hover: 0 16px 48px rgba(26, 115, 232, 0.18);
  --radius-sm: 8px;
  --radius: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  --gradient-banner: linear-gradient(135deg, #1a73e8 0%, #6c5ce7 40%, #00c9a7 100%);
  --gradient-card: linear-gradient(135deg, rgba(255,255,255,0.9), rgba(255,255,255,0.6));
  --gradient-accent: linear-gradient(135deg, #1a73e8, #00c9a7);
  --glass-bg: rgba(255, 255, 255, 0.18);
  --glass-border: rgba(255, 255, 255, 0.3);
  --glass-shadow: 0 8px 32px rgba(31, 38, 135, 0.15);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --max-width: 1200px;
  --header-height: 64px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #5a9cf5;
    --primary-dark: #4a8ae0;
    --primary-light: #7ab5ff;
    --accent: #00e6c3;
    --accent-dark: #00ccad;
    --bg: #0f0f1a;
    --bg-card: #1a1a2e;
    --bg-header: rgba(15, 15, 26, 0.78);
    --bg-nav: rgba(15, 15, 26, 0.65);
    --text: #e8e8f0;
    --text-secondary: #a0a0b8;
    --text-muted: #6a6a85;
    --border: #2a2a40;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
    --shadow-hover: 0 16px 48px rgba(90, 156, 245, 0.2);
    --gradient-banner: linear-gradient(135deg, #0d1b3e 0%, #1a1a4e 40%, #0a3d3d 100%);
    --gradient-card: linear-gradient(135deg, rgba(26,26,46,0.95), rgba(26,26,46,0.7));
    --glass-bg: rgba(26, 26, 46, 0.35);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition), color var(--transition);
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse 80% 60% at 10% 20%, rgba(26, 115, 232, 0.06), transparent),
    radial-gradient(ellipse 60% 50% at 90% 80%, rgba(0, 201, 167, 0.06), transparent);
  pointer-events: none;
  z-index: -1;
  transition: opacity var(--transition);
}

@media (prefers-color-scheme: dark) {
  body::before {
    background:
      radial-gradient(ellipse 80% 60% at 10% 20%, rgba(90, 156, 245, 0.08), transparent),
      radial-gradient(ellipse 60% 50% at 90% 80%, rgba(0, 230, 195, 0.06), transparent);
  }
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition), opacity var(--transition);
}

a:hover {
  color: var(--primary-light);
  opacity: 0.9;
}

a:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

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

ul {
  list-style: none;
}

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

h1 {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.35rem, 3vw, 2rem);
  margin-bottom: 1rem;
  position: relative;
  padding-bottom: 0.75rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 4px;
  border-radius: 2px;
  background: var(--gradient-accent);
  transition: width var(--transition);
}

section:hover > h2::after {
  width: 80px;
}

h3 {
  font-size: clamp(1.1rem, 2.2vw, 1.4rem);
  margin-bottom: 0.75rem;
  color: var(--text);
}

h4 {
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

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

p:last-child {
  margin-bottom: 0;
}

header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-header);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), box-shadow var(--transition);
}

header:hover {
  box-shadow: var(--shadow);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  min-height: var(--header-height);
  gap: 12px;
}

nav > p {
  margin: 0;
  flex-shrink: 0;
}

nav > p a {
  font-size: 1.3rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  letter-spacing: -0.02em;
  transition: opacity var(--transition), transform var(--transition);
  display: inline-block;
}

nav > p a:hover {
  opacity: 0.85;
  transform: scale(1.04);
  -webkit-text-fill-color: transparent;
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  align-items: center;
}

nav ul li a {
  display: block;
  padding: 6px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  white-space: nowrap;
  position: relative;
  transition: color var(--transition), background var(--transition), transform var(--transition);
}

nav ul li a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 60%;
  height: 2px;
  border-radius: 1px;
  background: var(--gradient-accent);
  transition: transform var(--transition);
}

nav ul li a:hover {
  color: var(--primary);
  background: rgba(26, 115, 232, 0.08);
  transform: translateY(-1px);
}

nav ul li a:hover::after {
  transform: translateX(-50%) scaleX(1);
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
}

article > section {
  margin-bottom: 32px;
  padding: 40px 36px;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateY(24px);
  animation: fadeInUp 0.7s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

article > section:nth-child(1) { animation-delay: 0.05s; }
article > section:nth-child(2) { animation-delay: 0.1s; }
article > section:nth-child(3) { animation-delay: 0.15s; }
article > section:nth-child(4) { animation-delay: 0.2s; }
article > section:nth-child(5) { animation-delay: 0.25s; }
article > section:nth-child(6) { animation-delay: 0.3s; }
article > section:nth-child(7) { animation-delay: 0.35s; }
article > section:nth-child(8) { animation-delay: 0.4s; }
article > section:nth-child(9) { animation-delay: 0.45s; }
article > section:nth-child(10) { animation-delay: 0.5s; }
article > section:nth-child(11) { animation-delay: 0.55s; }
article > section:nth-child(12) { animation-delay: 0.6s; }
article > section:nth-child(13) { animation-delay: 0.65s; }
article > section:nth-child(14) { animation-delay: 0.7s; }
article > section:nth-child(15) { animation-delay: 0.75s; }

article > section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition);
}

article > section:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
  border-color: rgba(26, 115, 232, 0.2);
}

article > section:hover::before {
  opacity: 1;
}

section#home {
  background: var(--gradient-banner);
  border: none;
  color: #ffffff;
  padding: 64px 40px;
  margin-top: 24px;
  position: relative;
  overflow: hidden;
}

section#home::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255,255,255,0.12), transparent 70%);
  pointer-events: none;
  animation: float 8s ease-in-out infinite;
}

section#home::after {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0,255,200,0.1), transparent 70%);
  pointer-events: none;
  animation: float 10s ease-in-out infinite reverse;
}

section#home h1 {
  color: #ffffff;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 12px rgba(0,0,0,0.15);
}

section#home p {
  color: rgba(255, 255, 255, 0.88);
  position: relative;
  z-index: 1;
  max-width: 800px;
  font-size: 1.05rem;
  line-height: 1.85;
}

section#home:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 60px rgba(26, 115, 232, 0.3);
  border-color: transparent;
}

section#home:hover::before {
  opacity: 0;
}

section h3 {
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  padding-left: 16px;
  border-left: 4px solid var(--primary);
  border-radius: 2px;
  transition: border-color var(--transition), padding-left var(--transition);
}

section h3:hover {
  border-left-color: var(--accent);
  padding-left: 20px;
}

section h4 {
  margin-top: 1.25rem;
  margin-bottom: 0.5rem;
  padding-left: 14px;
  border-left: 3px solid var(--accent);
  border-radius: 2px;
  transition: border-color var(--transition), padding-left var(--transition);
}

section h4:hover {
  border-left-color: var(--primary);
  padding-left: 18px;
}

section#articles article {
  margin-bottom: 20px;
  padding: 24px 28px;
  background: var(--bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition), background var(--transition);
  position: relative;
  overflow: hidden;
}

section#articles article::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition);
}

section#articles article:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px) translateX(4px);
  border-color: rgba(26, 115, 232, 0.2);
  background: var(--bg-card);
}

section#articles article:hover::before {
  opacity: 1;
}

section#articles article h3 {
  margin-top: 0;
  border-left: none;
  padding-left: 0;
  font-size: 1.15rem;
}

section#articles article h3:hover {
  border-left: none;
  padding-left: 0;
}

section#articles article p:first-of-type {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

section#articles article a {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 6px 18px;
  border-radius: 50px;
  background: var(--gradient-accent);
  color: #ffffff;
  -webkit-text-fill-color: #ffffff;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
}

section#articles article a:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 6px 20px rgba(26, 115, 232, 0.35);
  opacity: 0.92;
  color: #ffffff;
  -webkit-text-fill-color: #ffffff;
}

section#news h3 {
  margin-top: 1.5rem;
  border-left-color: var(--primary);
}

section#news h3 + p:first-of-type,
section#news h3 + p {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 0.02em;
}

section#news a {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 6px 18px;
  border-radius: 50px;
  background: var(--gradient-accent);
  color: #ffffff;
  -webkit-text-fill-color: #ffffff;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
}

section#news a:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 6px 20px rgba(26, 115, 232, 0.35);
  opacity: 0.92;
  color: #ffffff;
  -webkit-text-fill-color: #ffffff;
}

section#faq h3 {
  margin-top: 1.75rem;
  padding: 16px 20px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--primary);
  cursor: default;
  transition: background var(--transition), border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

section#faq h3:hover {
  background: var(--bg-card);
  border-left-color: var(--accent);
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
  padding-left: 24px;
}

section#faq h3 + p {
  padding: 0 20px 0 24px;
  margin-top: 8px;
}

section#howto h4 {
  margin-top: 1.5rem;
}

section#howto h4 + p {
  padding-left: 18px;
}

section#sitemap ul,
section#links ul {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px;
  margin-top: 12px;
}

section#sitemap ul li a,
section#links ul li a {
  display: block;
  padding: 10px 18px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  text-align: center;
  transition: all var(--transition);
}

section#sitemap ul li a:hover,
section#links ul li a:hover {
  background: var(--gradient-accent);
  color: #ffffff;
  -webkit-text-fill-color: #ffffff;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26, 115, 232, 0.3);
}

section#contact h3 {
  margin-top: 1.5rem;
}

section#contact p {
  padding-left: 8px;
}

footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 60px;
}

footer > section {
  margin-bottom: 24px;
  padding: 32px 36px;
  background: var(--glass-bg);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border-radius: var(--radius-lg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  transition: box-shadow var(--transition), transform var(--transition), background var(--transition);
}

footer > section:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

footer > section h2 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
}

footer > section h2::after {
  width: 32px;
  height: 3px;
}

footer > section:hover h2::after {
  width: 56px;
}

footer > section p {
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--text-secondary);
}

footer > p {
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 8px 0;
  letter-spacing: 0.01em;
  transition: color var(--transition);
}

footer > p:hover {
  color: var(--text-secondary);
}

@media (max-width: 1024px) {
  main {
    padding: 0 20px 60px;
  }

  article > section {
    padding: 32px 28px;
    border-radius: var(--radius);
  }

  section#home {
    padding: 48px 28px;
  }

  nav ul li a {
    padding: 5px 10px;
    font-size: 0.82rem;
  }

  footer {
    padding: 0 20px 40px;
  }

  footer > section {
    padding: 28px 24px;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 56px;
  }

  body {
    font-size: 15px;
    line-height: 1.7;
  }

  nav {
    padding: 0 16px;
    gap: 8px;
  }

  nav > p a {
    font-size: 1.1rem;
  }

  nav ul {
    gap: 2px;
  }

  nav ul li a {
    padding: 4px 8px;
    font-size: 0.75rem;
    border-radius: 6px;
  }

  main {
    padding: 0 16px 48px;
  }

  article > section {
    padding: 24px 20px;
    border-radius: var(--radius);
    margin-bottom: 20px;
  }

  section#home {
    padding: 36px 20px;
    margin-top: 16px;
    border-radius: var(--radius);
  }

  section#home h1 {
    font-size: 1.5rem;
  }

  section#home p {
    font-size: 0.92rem;
    line-height: 1.75;
  }

  h2 {
    font-size: 1.25rem;
  }

  h3 {
    font-size: 1.05rem;
    margin-top: 1.25rem;
  }

  section#articles article {
    padding: 18px 18px;
  }

  section#articles article h3 {
    font-size: 1.02rem;
  }

  section#faq h3 {
    padding: 12px 16px;
    font-size: 1rem;
  }

  section#faq h3:hover {
    padding-left: 20px;
  }

  section#faq h3 + p {
    padding: 0 16px 0 20px;
  }

  section#sitemap ul,
  section#links ul {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 8px;
  }

  section#sitemap ul li a,
  section#links ul li a {
    padding: 8px 12px;
    font-size: 0.82rem;
  }

  footer {
    padding: 0 16px 36px;
  }

  footer > section {
    padding: 22px 18px;
    border-radius: var(--radius);
  }

  footer > section h2 {
    font-size: 1.05rem;
  }

  footer > section p {
    font-size: 0.85rem;
  }

  footer > p {
    font-size: 0.75rem;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 14px;
  }

  nav {
    padding: 0 12px;
    min-height: 52px;
  }

  nav > p a {
    font-size: 1rem;
  }

  nav ul {
    gap: 1px;
  }

  nav ul li a {
    padding: 3px 6px;
    font-size: 0.7rem;
  }

  main {
    padding: 0 12px 36px;
  }

  article > section {
    padding: 20px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
  }

  section#home {
    padding: 28px 16px;
    margin-top: 12px;
    border-radius: var(--radius-sm);
  }

  section#home h1 {
    font-size: 1.3rem;
  }

  section#home p {
    font-size: 0.88rem;
  }

  h2 {
    font-size: 1.15rem;
  }

  h3 {
    font-size: 1rem;
  }

  section#articles article {
    padding: 14px 14px;
  }

  section#sitemap ul,
  section#links ul {
    grid-template-columns: repeat(2, 1fr);
    gap: 6px;
  }

  section#sitemap ul li a,
  section#links ul li a {
    padding: 7px 10px;
    font-size: 0.78rem;
  }

  footer {
    padding: 0 12px 28px;
  }

  footer > section {
    padding: 18px 14px;
    border-radius: var(--radius-sm);
  }
}

@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;
  }

  article > section {
    opacity: 1;
    transform: none;
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes shimmer {
  0% {
    background-position: -200% center;
  }
  100% {
    background-position: 200% center;
  }
}

@media print {
  header,
  nav,
  footer > section:not(#copyright),
  section#sitemap,
  section#links {
    display: none;
  }

  body {
    background: #ffffff;
    color: #000000;
    font-size: 12pt;
  }

  article > section {
    box-shadow: none;
    border: 1px solid #cccccc;
    break-inside: avoid;
    opacity: 1;
    transform: none;
    animation: none;
  }

  section#home {
    background: #f0f0f0;
    color: #000000;
  }

  section#home h1,
  section#home p {
    color: #000000;
  }

  a {
    color: #000000;
    text-decoration: underline;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
}