:root {
  --bg-deep: #0B1E3B;
  --bg-panel: #122A4A;
  --bg-hover: #1B3A5C;
  --bg-accent: #2E5F8E;
  --gold: #FFB347;
  --orange: #FF6B35;
  --white: #FFFFFF;
  --muted: #A9BFD4;
  --highlight: #FFD980;
  --line: rgba(0, 0, 0, 0.2);
  --font-display: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
  --radius-lg: 32px;
  --radius-md: 20px;
  --radius-sm: 12px;
  --radius-pill: 999px;
  --header-h: 68px;
  --container-max: 1440px;
  --container-pad: clamp(20px, 5vw, 80px);
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  font-family: var(--font-display);
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
  background-color: var(--bg-deep);
  background-image:
    radial-gradient(circle at 85% 8%, rgba(46, 95, 142, 0.18), transparent 42%),
    radial-gradient(circle at 8% 92%, rgba(255, 107, 53, 0.06), transparent 36%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1, h2, h3, h4, p, ul, ol, figure {
  margin-top: 0;
}

h1, h2, h3, h4 {
  color: var(--white);
  font-weight: 300;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

a {
  color: var(--gold);
  text-decoration: none;
}

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

button {
  font: inherit;
  color: inherit;
}

[id] {
  scroll-margin-top: 90px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 1000;
  padding: 12px 24px;
  background: var(--gold);
  color: var(--bg-deep);
  font-weight: 600;
  font-size: 14px;
  border-radius: 0 0 12px 12px;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
  color: var(--bg-deep);
}

#main-content {
  min-height: 70vh;
  outline: none;
  scroll-margin-top: 70px;
}

.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

.grid {
  display: grid;
  gap: 24px;
}

.grid-cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid-cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 24px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 15px;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease, background-color 0.25s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--gold), var(--orange));
  color: var(--bg-deep);
  box-shadow: 0 6px 24px rgba(255, 107, 53, 0.28);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 34px rgba(255, 107, 53, 0.4);
  color: var(--bg-deep);
}

.btn-secondary {
  background: transparent;
  color: var(--white);
  border-color: rgba(169, 191, 212, 0.32);
}

.btn-secondary:hover {
  border-color: var(--gold);
  color: var(--gold);
  transform: translateY(-2px);
}

.index-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.index-label::before {
  content: "";
  width: 20px;
  height: 1px;
  background: currentColor;
  opacity: 0.6;
}

.section-kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 12px;
}

.section-heading {
  font-family: var(--font-display);
  font-weight: 200;
  font-size: clamp(36px, 5vw, 72px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--white);
  margin-bottom: 24px;
}

.section-heading strong {
  font-weight: 600;
}

.content-body {
  font-size: 17px;
  line-height: 1.9;
  color: var(--muted);
}

.content-body h2 {
  font-size: 36px;
  font-weight: 200;
  margin: 48px 0 16px;
  color: var(--white);
}

.content-body p {
  margin-bottom: 16px;
}

.content-body ul,
.content-body ol {
  margin-bottom: 16px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  padding: 28px 0 0;
  margin: 0 0 24px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 10px;
  color: rgba(169, 191, 212, 0.4);
}

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

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

.breadcrumb [aria-current="page"] {
  color: var(--muted);
}

.card-group {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}

.card {
  background: var(--bg-panel);
  border: 1px solid rgba(169, 191, 212, 0.1);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: background-color 0.25s ease, transform 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  background: var(--bg-hover);
  border-color: rgba(255, 179, 71, 0.26);
  transform: translateY(-3px);
}

.card-title {
  font-size: 22px;
  font-weight: 400;
  color: var(--white);
  margin-bottom: 8px;
}

.card-summary {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 16px;
}

.card-link {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.card-link:hover {
  color: var(--highlight);
}

.acc {
  display: block;
  margin: 0;
  background: var(--bg-panel);
  border: 1px solid rgba(169, 191, 212, 0.12);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.acc[open] {
  border-color: rgba(255, 179, 71, 0.32);
}

.acc > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 22px;
  font-weight: 500;
  font-size: 16px;
  color: var(--white);
  cursor: pointer;
  list-style: none;
  user-select: none;
}

.acc > summary::-webkit-details-marker {
  display: none;
}

.acc > summary::after {
  content: "+";
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  flex: 0 0 28px;
  border-radius: 50%;
  background: rgba(255, 179, 71, 0.12);
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 18px;
  transition: transform 0.2s ease, background-color 0.2s ease;
}

.acc[open] > summary::after {
  content: "−";
  background: var(--gold);
  color: var(--bg-deep);
  transform: rotate(180deg);
}

.acc > div {
  padding: 0 22px 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.media-frame {
  position: relative;
  aspect-ratio: 16 / 9;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: linear-gradient(160deg, var(--bg-hover), var(--bg-deep) 85%);
  border: 1px solid rgba(169, 191, 212, 0.12);
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(255, 179, 71, 0.08), transparent 62%);
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 16px 20px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  background: linear-gradient(0deg, rgba(11, 30, 59, 0.9), transparent);
}

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-revealed] {
  opacity: 1;
  transform: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: rgba(11, 30, 59, 0.88);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(169, 191, 212, 0.14);
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--gold), var(--orange), transparent);
  opacity: 0.7;
}

.header-shell {
  position: relative;
  max-width: var(--container-max);
  min-height: var(--header-h);
  margin-inline: auto;
  padding-inline: var(--container-pad);
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  color: var(--white);
  font-family: var(--font-display);
  text-decoration: none;
}

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

.brand-glyph {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gold), var(--orange));
  color: var(--bg-deep);
  font-weight: 700;
  font-size: 16px;
  box-shadow: 0 0 22px rgba(255, 179, 71, 0.25);
}

.brand-text {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 13px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover {
  color: var(--white);
  background: rgba(27, 58, 92, 0.75);
  border-color: rgba(169, 191, 212, 0.12);
}

.nav-link[aria-current="page"] {
  color: var(--bg-deep);
  background: linear-gradient(135deg, var(--gold), var(--orange));
  font-weight: 600;
  box-shadow: 0 4px 18px rgba(255, 107, 53, 0.25);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 24px;
  border-radius: var(--radius-pill);
  border: none;
  background: linear-gradient(135deg, var(--gold), var(--orange));
  color: var(--bg-deep);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  box-shadow: 0 6px 24px rgba(255, 107, 53, 0.28);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.header-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 34px rgba(255, 107, 53, 0.4);
  color: var(--bg-deep);
}

.header-cta--standalone {
  margin-left: 16px;
  flex-shrink: 0;
}

.nav-cta {
  display: none;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid rgba(169, 191, 212, 0.28);
  border-radius: 14px;
  background: transparent;
  cursor: pointer;
  margin-left: auto;
}

.toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--white);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--orange));
  transform: scaleX(0);
  transform-origin: left;
  z-index: 10;
  pointer-events: none;
}

.site-footer {
  position: relative;
  margin-top: 120px;
  background: linear-gradient(180deg, rgba(18, 42, 74, 0.5), rgba(11, 30, 59, 1) 55%);
  border-top: 1px solid rgba(169, 191, 212, 0.16);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 5%, var(--gold), var(--orange), transparent 95%);
  opacity: 0.8;
}

.footer-shell {
  max-width: var(--container-max);
  margin-inline: auto;
  padding: 72px var(--container-pad) 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1.4fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(169, 191, 212, 0.12);
}

.footer-brand-block,
.footer-index-block,
.footer-contact-block {
  min-width: 0;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.footer-brand .brand-glyph {
  width: 38px;
  height: 38px;
  font-size: 15px;
}

.footer-brand .brand-text {
  font-size: 18px;
}

.footer-about {
  font-size: 16px;
  color: var(--white);
  margin-bottom: 8px;
}

.footer-note {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 0;
}

.footer-title {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 18px;
}

.footer-nav {
  display: grid;
  gap: 8px;
}

.footer-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 15px;
  text-decoration: none;
  padding: 4px 0;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-nav a::before {
  content: "↗";
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--gold);
  opacity: 0.7;
}

.footer-nav a:hover {
  color: var(--white);
  transform: translateX(2px);
}

.footer-contact {
  display: grid;
  gap: 8px;
}

.footer-contact-item {
  display: inline-flex;
  color: var(--muted);
  font-size: 15px;
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-contact-item:hover {
  color: var(--gold);
}

.footer-trust {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(169, 191, 212, 0.8);
  border-left: 2px solid rgba(255, 179, 71, 0.5);
  padding-left: 12px;
}

.footer-meta-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding-top: 24px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.05em;
  color: rgba(169, 191, 212, 0.72);
}

.footer-tech {
  color: rgba(255, 179, 71, 0.7);
}

:where(a, button, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 4px;
}

@media (max-width: 1100px) {
  .header-shell {
    min-height: 60px;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .header-cta--standalone {
    display: none;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-left: 0;
    padding: 16px var(--container-pad) 24px;
    background: linear-gradient(180deg, rgba(11, 30, 59, 0.98), rgba(18, 42, 74, 0.98));
    border-bottom: 1px solid rgba(169, 191, 212, 0.12);
    box-shadow: 0 24px 40px rgba(0, 0, 0, 0.35);
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease;
  }

  .site-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-link {
    width: 100%;
    padding: 12px 16px;
    font-size: 15px;
    border-radius: var(--radius-sm);
  }

  .nav-link[aria-current="page"] {
    background: linear-gradient(135deg, var(--gold), var(--orange));
    box-shadow: 0 4px 18px rgba(255, 107, 53, 0.2);
  }

  .nav-cta {
    display: inline-flex;
    justify-content: center;
    width: 100%;
    margin-top: 14px;
  }
}

@media (max-width: 760px) {
  .grid-cols-2,
  .grid-cols-3 {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-meta-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

@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;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}