:root {
  --primary: #1f6feb;
  --primary-dark: #1557b0;
  --primary-light: #4a8ef5;
  --accent: #7c3aed;
  --accent-light: #a78bfa;
  --gradient-1: linear-gradient(135deg, #1f6feb 0%, #7c3aed 50%, #ec4899 100%);
  --gradient-2: linear-gradient(135deg, #0ea5e9 0%, #6366f1 50%, #a855f7 100%);
  --gradient-3: linear-gradient(160deg, #1e3a8a 0%, #4c1d95 40%, #831843 100%);
  --bg-body: #f5f7fb;
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.65);
  --bg-glass-border: rgba(255, 255, 255, 0.8);
  --text-main: #1a1f36;
  --text-sub: #4a5568;
  --text-muted: #718096;
  --border-color: rgba(31, 111, 235, 0.12);
  --shadow-sm: 0 2px 8px rgba(31, 111, 235, 0.06);
  --shadow-md: 0 8px 24px rgba(31, 111, 235, 0.1);
  --shadow-lg: 0 16px 48px rgba(31, 111, 235, 0.14);
  --shadow-glow: 0 0 40px rgba(31, 111, 235, 0.2);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --nav-height: 64px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-body: #0d1117;
    --bg-card: #161b22;
    --bg-glass: rgba(22, 27, 34, 0.7);
    --bg-glass-border: rgba(255, 255, 255, 0.08);
    --text-main: #e6edf3;
    --text-sub: #b1bac4;
    --text-muted: #8b949e;
    --border-color: rgba(255, 255, 255, 0.08);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(31, 111, 235, 0.15);
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 20px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-body);
  color: var(--text-main);
  line-height: 1.75;
  font-size: 16px;
  overflow-x: hidden;
  transition: background-color var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse 80% 60% at 10% 0%, rgba(31, 111, 235, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 90% 20%, rgba(124, 58, 237, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse 70% 50% at 50% 100%, rgba(236, 72, 153, 0.04) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

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

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

nav[aria-label="主导航"] {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

nav[aria-label="主导航"] > a {
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
  background: var(--gradient-1);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
  transition: opacity var(--transition);
  letter-spacing: -0.01em;
}

nav[aria-label="主导航"] > a:hover {
  opacity: 0.8;
}

nav[aria-label="主导航"] ul {
  display: flex;
  list-style: none;
  gap: 4px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

nav[aria-label="主导航"] ul li a {
  display: inline-block;
  padding: 6px 12px;
  font-size: 0.875rem;
  color: var(--text-sub);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  position: relative;
  white-space: nowrap;
}

nav[aria-label="主导航"] ul li a::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-1);
  border-radius: 2px;
  transition: all var(--transition);
  transform: translateX(-50%);
}

nav[aria-label="主导航"] ul li a:hover {
  color: var(--primary);
  background: rgba(31, 111, 235, 0.06);
}

nav[aria-label="主导航"] ul li a:hover::after {
  width: 60%;
}

/* ============ MAIN LAYOUT ============ */
main {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 80px;
}

/* ============ HERO SECTION ============ */
section[aria-labelledby="hero-title"] {
  position: relative;
  margin: 40px 0 56px;
  padding: 64px 48px;
  border-radius: var(--radius-xl);
  background: var(--gradient-3);
  color: #ffffff;
  overflow: hidden;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  animation: fadeInUp 0.8s ease-out both;
}

section[aria-labelledby="hero-title"]::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.12) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 8s ease-in-out infinite;
}

section[aria-labelledby="hero-title"]::after {
  content: "";
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(236, 72, 153, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(30px, -30px) scale(1.05); }
}

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

section[aria-labelledby="hero-title"] h1 {
  position: relative;
  z-index: 1;
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}

section[aria-labelledby="hero-title"] p {
  position: relative;
  z-index: 1;
  font-size: 1.05rem;
  line-height: 1.9;
  opacity: 0.92;
  max-width: 800px;
  margin-bottom: 16px;
}

section[aria-labelledby="hero-title"] p:last-of-type {
  margin-bottom: 28px;
}

/* Breadcrumb */
nav[aria-label="面包屑导航"] {
  position: relative;
  z-index: 1;
}

nav[aria-label="面包屑导航"] ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  font-size: 0.85rem;
}

nav[aria-label="面包屑导航"] ol li {
  display: flex;
  align-items: center;
  gap: 8px;
  color: rgba(255, 255, 255, 0.7);
}

nav[aria-label="面包屑导航"] ol li + li::before {
  content: "/";
  opacity: 0.5;
}

nav[aria-label="面包屑导航"] ol li a {
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  transition: all var(--transition);
}

nav[aria-label="面包屑导航"] ol li a:hover {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

/* ============ SECTIONS ============ */
main > section:not([aria-labelledby="hero-title"]) {
  margin-bottom: 56px;
  padding: 48px 40px;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  animation: fadeInUp 0.7s ease-out both;
  animation-timeline: view();
  animation-range: entry 0% entry 30%;
}

main > section:not([aria-labelledby="hero-title"]):hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(31, 111, 235, 0.2);
}

main > section h2 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 24px;
  padding-bottom: 16px;
  position: relative;
  letter-spacing: -0.01em;
  color: var(--text-main);
}

main > section h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: var(--gradient-1);
  border-radius: 4px;
  transition: width var(--transition);
}

main > section:hover h2::after {
  width: 100px;
}

main > section h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 28px 0 12px;
  color: var(--text-main);
  position: relative;
  padding-left: 16px;
}

main > section h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 1.1em;
  background: var(--gradient-1);
  border-radius: 2px;
}

main > section p {
  color: var(--text-sub);
  margin-bottom: 14px;
  line-height: 1.85;
}

main > section ul,
main > section ol {
  margin: 16px 0;
  padding-left: 24px;
  color: var(--text-sub);
}

main > section ul li,
main > section ol li {
  margin-bottom: 10px;
  line-height: 1.8;
  position: relative;
}

main > section ul li::marker {
  color: var(--primary);
}

main > section ol li::marker {
  color: var(--primary);
  font-weight: 600;
}

main > section ul li a,
main > section ol li a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}

main > section ul li a:hover,
main > section ol li a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ============ ARTICLES ============ */
main article {
  padding: 24px 28px;
  margin-bottom: 20px;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--bg-glass-border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

main article::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient-1);
  opacity: 0;
  transition: opacity var(--transition);
}

main article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(31, 111, 235, 0.25);
}

main article:hover::before {
  opacity: 1;
}

main article h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0 0 8px;
  padding-left: 0;
  color: var(--text-main);
  transition: color var(--transition);
}

main article h3::before {
  display: none;
}

main article:hover h3 {
  color: var(--primary);
}

main article p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

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

main article p a {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9rem;
  transition: all var(--transition);
}

main article p a::after {
  content: "→";
  transition: transform var(--transition);
}

main article p a:hover {
  color: var(--accent);
}

main article p a:hover::after {
  transform: translateX(4px);
}

/* ============ FAQ ============ */
section[aria-labelledby="faq-title"] h3 {
  padding: 16px 20px;
  margin: 12px 0 0;
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--bg-glass-border);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  cursor: pointer;
  transition: all var(--transition);
  font-size: 1.05rem;
  padding-left: 20px;
}

section[aria-labelledby="faq-title"] h3::before {
  display: none;
}

section[aria-labelledby="faq-title"] h3:hover {
  background: rgba(31, 111, 235, 0.06);
  border-color: rgba(31, 111, 235, 0.2);
  color: var(--primary);
}

section[aria-labelledby="faq-title"] h3 + p {
  padding: 16px 20px;
  margin: 0 0 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  font-size: 0.95rem;
  color: var(--text-sub);
}

/* ============ HOWTO ============ */
section[aria-labelledby="howto-title"] ol {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

section[aria-labelledby="howto-title"] ol li {
  counter-increment: step;
  padding: 16px 20px 16px 64px;
  margin-bottom: 12px;
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--bg-glass-border);
  border-radius: var(--radius-md);
  position: relative;
  transition: all var(--transition);
}

section[aria-labelledby="howto-title"] ol li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-1);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.85rem;
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(31, 111, 235, 0.3);
}

section[aria-labelledby="howto-title"] ol li:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
  border-color: rgba(31, 111, 235, 0.25);
}

/* ============ CONTACT ============ */
section[aria-labelledby="contact-title"] ul {
  list-style: none;
  padding-left: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

section[aria-labelledby="contact-title"] ul li {
  padding: 20px 24px;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--bg-glass-border);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

section[aria-labelledby="contact-title"] ul li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-1);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

section[aria-labelledby="contact-title"] ul li:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

section[aria-labelledby="contact-title"] ul li:hover::before {
  transform: scaleX(1);
}

/* ============ SITEMAP & LINKS ============ */
section[aria-labelledby="sitemap-title"] ul,
section[aria-labelledby="links-title"] ul {
  list-style: none;
  padding-left: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

section[aria-labelledby="sitemap-title"] ul li,
section[aria-labelledby="links-title"] ul li {
  margin-bottom: 0;
}

section[aria-labelledby="sitemap-title"] ul li a,
section[aria-labelledby="links-title"] ul li a {
  display: inline-block;
  padding: 10px 20px;
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--bg-glass-border);
  border-radius: 50px;
  color: var(--text-sub);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition);
}

section[aria-labelledby="sitemap-title"] ul li a:hover,
section[aria-labelledby="links-title"] ul li a:hover {
  background: var(--gradient-1);
  color: #ffffff;
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(31, 111, 235, 0.3);
}

/* ============ LEGAL ============ */
section[aria-labelledby="legal-title"] h3 {
  margin-top: 24px;
}

section[aria-labelledby="legal-title"] p {
  font-size: 0.92rem;
  color: var(--text-muted);
  padding: 16px 20px;
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--primary);
}

/* ============ AUTHOR ============ */
section[aria-labelledby="author-title"] p {
  padding: 16px 20px;
  background: var(--bg-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: var(--radius-md);
  border: 1px solid var(--bg-glass-border);
  font-size: 0.92rem;
}

/* ============ FOOTER ============ */
footer {
  position: relative;
  z-index: 1;
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding: 40px 24px;
  text-align: center;
  transition: background-color var(--transition);
}

footer p {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 8px;
}

footer p a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  padding: 8px 20px;
  border-radius: 50px;
  background: rgba(31, 111, 235, 0.08);
  transition: all var(--transition);
}

footer p a::before {
  content: "↑";
  font-size: 0.9rem;
  transition: transform var(--transition);
}

footer p a:hover {
  background: var(--gradient-1);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(31, 111, 235, 0.3);
}

footer p a:hover::before {
  transform: translateY(-2px);
}

/* ============ SCROLL ANIMATIONS ============ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@supports (animation-timeline: view()) {
  main > section {
    animation: fadeInUp 0.7s ease-out both;
    animation-timeline: view();
    animation-range: entry 0% entry 25%;
  }
}

/* ============ RESPONSIVE ============ */
@media (max-width: 1024px) {
  section[aria-labelledby="hero-title"] {
    padding: 48px 36px;
  }

  section[aria-labelledby="hero-title"] h1 {
    font-size: 2rem;
  }

  main > section:not([aria-labelledby="hero-title"]) {
    padding: 40px 32px;
  }
}

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

  nav[aria-label="主导航"] {
    padding: 0 16px;
    flex-direction: column;
    height: auto;
    padding-top: 12px;
    padding-bottom: 12px;
    gap: 10px;
  }

  nav[aria-label="主导航"] ul {
    justify-content: center;
    gap: 2px;
  }

  nav[aria-label="主导航"] ul li a {
    padding: 5px 8px;
    font-size: 0.78rem;
  }

  main {
    padding: 0 16px 60px;
  }

  section[aria-labelledby="hero-title"] {
    margin: 24px 0 36px;
    padding: 36px 24px;
    border-radius: var(--radius-lg);
  }

  section[aria-labelledby="hero-title"] h1 {
    font-size: 1.5rem;
  }

  section[aria-labelledby="hero-title"] p {
    font-size: 0.95rem;
  }

  main > section:not([aria-labelledby="hero-title"]) {
    padding: 28px 20px;
    margin-bottom: 36px;
    border-radius: var(--radius-md);
  }

  main > section h2 {
    font-size: 1.35rem;
  }

  main > section h3 {
    font-size: 1.05rem;
  }

  main article {
    padding: 18px 20px;
  }

  section[aria-labelledby="contact-title"] ul {
    grid-template-columns: 1fr;
  }

  section[aria-labelledby="howto-title"] ol li {
    padding: 14px 16px 14px 56px;
  }

  section[aria-labelledby="howto-title"] ol li::before {
    left: 12px;
    width: 28px;
    height: 28px;
    font-size: 0.78rem;
  }

  section[aria-labelledby="sitemap-title"] ul,
  section[aria-labelledby="links-title"] ul {
    gap: 8px;
  }

  section[aria-labelledby="sitemap-title"] ul li a,
  section[aria-labelledby="links-title"] ul li a {
    padding: 8px 16px;
    font-size: 0.82rem;
  }

  footer {
    padding: 28px 16px;
  }
}

@media (max-width: 480px) {
  nav[aria-label="主导航"] > a {
    font-size: 0.95rem;
  }

  nav[aria-label="主导航"] ul li a {
    padding: 4px 6px;
    font-size: 0.72rem;
  }

  section[aria-labelledby="hero-title"] {
    padding: 28px 18px;
  }

  section[aria-labelledby="hero-title"] h1 {
    font-size: 1.25rem;
  }

  section[aria-labelledby="hero-title"] p {
    font-size: 0.88rem;
  }

  main > section:not([aria-labelledby="hero-title"]) {
    padding: 22px 16px;
  }

  main > section h2 {
    font-size: 1.2rem;
  }

  main article {
    padding: 14px 16px;
  }

  main article h3 {
    font-size: 1rem;
  }
}

/* ============ ACCESSIBILITY ============ */
@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;
  }
}

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

::selection {
  background: rgba(31, 111, 235, 0.25);
  color: var(--text-main);
}

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

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(31, 111, 235, 0.25);
  border-radius: 10px;
  border: 2px solid transparent;
  background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(31, 111, 235, 0.45);
  background-clip: content-box;
}