:root {
  --primary: #1a3a5c;
  --primary-light: #2d6a9f;
  --accent: #f0b429;
  --accent-soft: #f7d070;
  --bg: #f4f7fb;
  --bg-elevated: #ffffff;
  --bg-soft: #eef3f8;
  --text: #1c2b3a;
  --text-secondary: #4a5b6d;
  --text-muted: #78899b;
  --border: rgba(26, 58, 92, 0.12);
  --glass-bg: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(255, 255, 255, 0.55);
  --shadow-sm: 0 2px 8px rgba(26, 58, 92, 0.06);
  --shadow-md: 0 8px 28px rgba(26, 58, 92, 0.10);
  --shadow-lg: 0 18px 48px rgba(26, 58, 92, 0.16);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --max-width: 1180px;
  --header-h: 72px;
  --transition: 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
  --gradient-hero: linear-gradient(135deg, #eaf1f9 0%, #dfeaf5 40%, #f7efd8 100%);
  --gradient-btn: linear-gradient(135deg, #1a3a5c 0%, #2d6a9f 100%);
  --gradient-accent: linear-gradient(135deg, #f0b429 0%, #f7d070 100%);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #8fb8e0;
    --primary-light: #a9cbec;
    --accent: #f0b429;
    --accent-soft: #c99a2a;
    --bg: #0d1620;
    --bg-elevated: #15212e;
    --bg-soft: #1a2938;
    --text: #e7eef6;
    --text-secondary: #b3c2d1;
    --text-muted: #8397a9;
    --border: rgba(143, 184, 224, 0.16);
    --glass-bg: rgba(21, 33, 46, 0.7);
    --glass-border: rgba(143, 184, 224, 0.18);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 18px 48px rgba(0, 0, 0, 0.55);
    --gradient-hero: linear-gradient(135deg, #12202e 0%, #16283a 45%, #2a2416 100%);
    --gradient-btn: linear-gradient(135deg, #2d6a9f 0%, #4a8cc4 100%);
  }
}

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

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

body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image: radial-gradient(circle at 12% 8%, rgba(45, 106, 159, 0.08) 0%, transparent 42%),
    radial-gradient(circle at 88% 4%, rgba(240, 180, 41, 0.08) 0%, transparent 38%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

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

h1, h2, h3, h4 {
  line-height: 1.35;
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0.01em;
}

h1 {
  font-size: clamp(1.7rem, 3.6vw, 2.6rem);
  margin: 0 0 1rem;
}

h2 {
  font-size: clamp(1.35rem, 2.6vw, 1.9rem);
  margin: 0 0 1.2rem;
  position: relative;
  padding-left: 0.9rem;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
}

h3 {
  font-size: clamp(1.08rem, 1.8vw, 1.28rem);
  margin: 1.6rem 0 0.6rem;
}

p {
  margin: 0 0 1rem;
  color: var(--text-secondary);
}

ul, ol {
  margin: 0 0 1.2rem;
  padding-left: 1.4rem;
  color: var(--text-secondary);
}

li {
  margin-bottom: 0.5rem;
}

strong {
  color: var(--text);
  font-weight: 600;
}

blockquote {
  margin: 1.2rem 0;
  padding: 1rem 1.4rem;
  border-left: 4px solid var(--accent);
  background: var(--bg-soft);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--text-secondary);
  font-style: italic;
}

blockquote p {
  margin: 0 0 0.6rem;
}

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

/* ============ Header ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
  padding: 8px 0;
}

.brand:hover {
  color: var(--text);
}

.brand-logo {
  border-radius: 9px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition);
}

.brand:hover .brand-logo {
  transform: rotate(-6deg) scale(1.06);
}

.brand-text {
  letter-spacing: 0.04em;
}

.main-nav ul {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.main-nav a {
  display: inline-block;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  color: var(--text-secondary);
  font-size: 0.94rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.main-nav a:hover {
  background: var(--bg-soft);
  color: var(--primary-light);
  transform: translateY(-1px);
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 18px 24px 6px;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-muted);
}

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

.breadcrumb [aria-current="page"] {
  color: var(--primary-light);
  font-weight: 600;
}

/* ============ Main layout ============ */
main {
  display: block;
}

main > section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 32px 24px;
  animation: fadeUp 0.7s ease both;
}

main > section:nth-of-type(even) {
  animation-delay: 0.05s;
}

main > section article {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 30px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}

main > section article:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(45, 106, 159, 0.25);
}

main > section article > h3:first-child {
  margin-top: 0;
}

/* ============ Hero ============ */
.hero {
  max-width: var(--max-width);
  margin: 12px auto 0;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 36px;
  align-items: center;
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  border-radius: var(--radius-lg);
  z-index: -1;
  animation: gradientShift 14s ease-in-out infinite alternate;
  background-size: 200% 200%;
}

.hero-content {
  padding: 48px 8px 48px 36px;
}

.hero-content h1 {
  background: linear-gradient(120deg, var(--primary) 0%, var(--primary-light) 60%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: var(--primary);
}

.hero-lead {
  font-size: 1.02rem;
  color: var(--text-secondary);
  max-width: 640px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 26px;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 30px;
  border-radius: var(--radius-pill);
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
  will-change: transform;
}

.btn-primary {
  background: var(--gradient-btn);
  color: #ffffff;
  box-shadow: 0 10px 24px rgba(26, 58, 92, 0.28);
}

.btn-primary:hover {
  color: #ffffff;
  transform: translateY(-3px);
  box-shadow: 0 16px 32px rgba(26, 58, 92, 0.36);
}

.btn-secondary {
  background: var(--glass-bg);
  color: var(--primary-light);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}

.hero-visual {
  padding: 24px 36px 24px 0;
  animation: floatY 6s ease-in-out infinite;
}

.hero-visual svg {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

/* ============ Anchor nav ============ */
.anchor-nav {
  max-width: var(--max-width);
  margin: 4px auto 0;
  padding: 8px 24px 0;
}

.anchor-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.anchor-nav a {
  display: inline-block;
  padding: 8px 18px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-pill);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: all var(--transition);
}

.anchor-nav a:hover {
  color: #ffffff;
  background: var(--gradient-btn);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ============ Meta line ============ */
.meta-line {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0.6rem 0;
}

/* ============ Article cards ============ */
.article-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px 26px;
  margin-bottom: 18px;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.article-card::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(240, 180, 41, 0.4);
}

.article-card:hover::after {
  opacity: 1;
}

.article-card h3 {
  margin-top: 0;
  color: var(--primary-light);
}

.article-card a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--accent);
}

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

.article-card a:hover::after {
  transform: translateX(4px);
}

/* ============ FAQ ============ */
.faq-item {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 20px 26px;
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.faq-item:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(45, 106, 159, 0.3);
}

.faq-item h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  color: var(--primary-light);
  display: flex;
  gap: 10px;
}

.faq-item h3::before {
  content: "Q";
  flex: 0 0 auto;
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--gradient-btn);
  border-radius: 50%;
  margin-top: 2px;
}

.faq-item p {
  margin: 0;
  padding-left: 34px;
  font-size: 0.95rem;
}

/* ============ Footer ============ */
.site-footer {
  margin-top: 48px;
  background: linear-gradient(160deg, #12283c 0%, #1a3a5c 55%, #234a70 100%);
  color: #c9d7e4;
  border-top: 4px solid var(--accent);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px 36px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 32px;
}

.footer-inner h2 {
  font-size: 1.05rem;
  color: #ffffff;
  padding-left: 0;
  margin-bottom: 0.9rem;
}

.footer-inner h2::before {
  display: none;
}

.footer-inner h3 {
  font-size: 0.98rem;
  color: var(--accent-soft);
  margin: 0 0 0.6rem;
}

.footer-inner p {
  color: #b0c2d3;
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-inner ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-inner ul li {
  margin-bottom: 0.5rem;
}

.footer-inner a {
  color: #c9d7e4;
  font-size: 0.9rem;
  transition: color var(--transition), padding-left var(--transition);
}

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

.site-footer section {
  animation: fadeUp 0.8s ease both;
}

.site-footer section:nth-child(2) {
  animation-delay: 0.08s;
}

.site-footer section:nth-child(3) {
  animation-delay: 0.16s;
}

/* ============ Sitemap / Links ============ */
#sitemap nav ul,
#links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  padding: 0;
  margin: 0;
}

#sitemap nav a,
#links a {
  display: inline-block;
  padding: 7px 16px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  background: var(--bg-soft);
  border-radius: var(--radius-pill);
  transition: all var(--transition);
}

#sitemap nav a:hover,
#links a:hover {
  color: #ffffff;
  background: var(--gradient-btn);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* ============ Animations ============ */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes floatY {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-12px);
  }
}

@keyframes gradientShift {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 100% 50%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============ Responsive ============ */
@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .hero-content {
    padding: 40px 28px 8px;
  }

  .hero-visual {
    padding: 8px 28px 36px;
    animation: none;
  }

  .hero-visual svg {
    height: auto;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 64px;
  }

  .header-inner {
    padding: 0 16px;
    gap: 8px;
  }

  .brand-text {
    font-size: 1.02rem;
  }

  .main-nav {
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 6px;
  }

  .main-nav::-webkit-scrollbar {
    display: none;
  }

  .main-nav ul {
    flex-wrap: nowrap;
    gap: 2px;
  }

  .main-nav a {
    white-space: nowrap;
    padding: 7px 12px;
    font-size: 0.88rem;
  }

  .breadcrumb,
  .hero,
  .anchor-nav,
  main > section {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero {
    padding-left: 0;
    padding-right: 0;
    margin-left: 16px;
    margin-right: 16px;
    border-radius: var(--radius-md);
  }

  .hero::before {
    border-radius: var(--radius-md);
  }

  .hero-content {
    padding: 32px 22px 4px;
  }

  .hero-visual {
    padding: 4px 22px 28px;
  }

  main > section {
    padding-top: 22px;
    padding-bottom: 22px;
  }

  main > section article {
    padding: 20px 18px;
    border-radius: var(--radius-md);
  }

  .article-card,
  .faq-item {
    padding: 18px 18px;
  }

  .faq-item p {
    padding-left: 0;
  }

  .btn-primary,
  .btn-secondary {
    flex: 1 1 auto;
    padding: 12px 22px;
    font-size: 0.94rem;
  }

  .footer-inner {
    padding: 36px 16px 28px;
    gap: 24px;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  h2 {
    padding-left: 0.75rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
  }

  .anchor-nav ul {
    gap: 8px;
  }

  .anchor-nav a {
    padding: 7px 13px;
    font-size: 0.82rem;
  }
}

/* ============ Print ============ */
@media print {
  .site-header,
  .anchor-nav,
  .hero-visual,
  .hero-actions,
  .site-footer {
    display: none;
  }

  body {
    background: #ffffff;
    color: #000000;
  }

  main > section article,
  .article-card,
  .faq-item {
    box-shadow: none;
    border: 1px solid #cccccc;
    page-break-inside: avoid;
  }
}