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

:root {
  --header-h: 4.75rem;
  --font-heading: "Exo 2", "Avenir Next", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --color-space: #0B1D3A;
  --color-space-deep: #081226;
  --color-navy: #1E1E2E;
  --color-electric: #00D4FF;
  --color-purple: #9B59B6;
  --color-orange: #FF6B35;
  --color-light: #F5F7FA;
  --color-ink: #111827;
  --color-muted: #9EB0CC;
  --color-border: rgba(255, 255, 255, 0.1);
  --shadow-sm: 0 0.25rem 1rem rgba(0, 0, 0, 0.2);
  --shadow-md: 0 0.75rem 2rem rgba(0, 0, 0, 0.35);
  --radius: 0.75rem;
  --section-space: clamp(3.5rem, 8vw, 7rem);
}

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  min-height: 100vh;
  background-color: var(--color-space);
  background-image:
    radial-gradient(38rem 28rem at 85% -5%, rgba(155, 89, 182, 0.22), transparent 60%),
    radial-gradient(32rem 24rem at 10% 20%, rgba(0, 212, 255, 0.12), transparent 60%),
    linear-gradient(180deg, #0B1D3A 0%, #081226 100%);
  color: var(--color-light);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: 0.02em;
}

::selection {
  background: var(--color-electric);
  color: var(--color-space);
}

a {
  color: var(--color-electric);
  text-decoration-thickness: 0.05em;
  text-underline-offset: 0.25em;
}

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

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

button, input, select, textarea { font: inherit; color: inherit; }

ul, ol { list-style: none; }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: 1.15;
  text-wrap: balance;
  color: var(--color-white);
}

p { text-wrap: pretty; }

:focus-visible {
  outline: 2px solid var(--color-electric);
  outline-offset: 3px;
  border-radius: 2px;
}

#main-content {
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

#main-content:focus { outline: none; }

.container {
  width: min(100% - clamp(1.25rem, 4vw, 2.5rem), 75rem);
  margin-inline: auto;
}

.site-main {
  position: relative;
  z-index: 0;
  display: block;
  min-height: 70vh;
  padding-top: calc(var(--header-h) + 1.75rem);
}

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

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 200;
  display: inline-flex;
  padding: 0.75rem 1.25rem;
  background: var(--color-electric);
  color: var(--color-space);
  font-weight: 700;
  text-decoration: none;
  border-radius: 0.375rem;
  transform: translateY(-4rem);
  opacity: 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
  opacity: 1;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  background: linear-gradient(180deg, rgba(11, 29, 58, 0.92) 0%, rgba(11, 29, 58, 0.65) 65%, rgba(11, 29, 58, 0) 100%);
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image:
    radial-gradient(1px 1px at 18% 35%, rgba(255, 255, 255, 0.7), transparent 1px),
    radial-gradient(1px 1px at 68% 18%, rgba(0, 212, 255, 0.85), transparent 1px),
    radial-gradient(1.5px 1.5px at 44% 78%, rgba(155, 89, 182, 0.8), transparent 2px);
}

.site-header[data-scrolled="true"] {
  background: rgba(8, 18, 38, 0.97);
  border-bottom-color: rgba(0, 212, 255, 0.22);
  box-shadow: var(--shadow-md);
}

.site-header[data-scrolled="true"]::before { opacity: 0.15; }

.header-inner {
  position: relative;
  z-index: 1;
  max-width: 75rem;
  height: 100%;
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 4vw, 2.5rem);
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
  color: var(--color-white);
  text-decoration: none;
}

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

.brand-mark {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  background: linear-gradient(135deg, var(--color-electric), var(--color-purple));
  color: var(--color-space);
  font-size: 1.25rem;
  border-radius: 0.25rem;
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
  transform: rotate(-4deg);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.25);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: 0.04em;
}

.brand-tagline {
  margin-top: 0.25rem;
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-electric);
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(0.875rem, 2vw, 2rem);
}

.nav-list a {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 2.5rem;
  color: rgba(245, 247, 250, 0.85);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-decoration: none;
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0.25rem;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--color-electric), var(--color-purple));
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.25s ease;
}

.nav-list a:hover::after,
.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
  transform-origin: left;
}

.nav-list a:hover,
.nav-list a[aria-current="page"] {
  color: var(--color-white);
}

.nav-toggle {
  display: none;
  position: relative;
  z-index: 2;
  width: 3rem;
  height: 3rem;
  padding: 0.6rem 0.7rem;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 0.375rem;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 1.25rem;
  height: 2px;
  background: var(--color-electric);
}

.nav-toggle-bar + .nav-toggle-bar { margin-top: 5px; }

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

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

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

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.6rem;
  padding: 0.65rem 1.1rem;
  flex-shrink: 0;
  background: rgba(0, 212, 255, 0.1);
  border: 1px solid rgba(0, 212, 255, 0.4);
  border-radius: 0.375rem;
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-decoration: none;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 8px, 100% 100%, 8px 100%, 0 calc(100% - 8px));
  transition: background 0.25s ease, border-color 0.25s ease, color 0.25s ease;
}

.header-cta:hover {
  background: rgba(0, 212, 255, 0.22);
  border-color: rgba(255, 255, 255, 0.25);
  color: var(--color-white);
}

@media (max-width: 960px) {
  :root { --header-h: 4.25rem; }

  .header-cta { display: none; }

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

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 99;
    display: block;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    transform: translateY(-0.5rem);
    background: rgba(8, 18, 38, 0.98);
    border-bottom: 1px solid transparent;
    transition: max-height 0.3s ease, opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease, border-color 0.25s ease;
  }

  .site-nav[data-open="true"] {
    max-height: calc(100vh - var(--header-h));
    overflow: auto;
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
    border-bottom-color: rgba(0, 212, 255, 0.25);
    box-shadow: var(--shadow-md);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.75rem 1rem 1rem;
  }

  .nav-list a {
    min-height: 3rem;
    padding: 0.5rem 0.75rem;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 0.25rem;
    justify-content: space-between;
  }

  .nav-list a::after { display: none; }

  .nav-list a[aria-current="page"] {
    background: rgba(0, 212, 255, 0.1);
  }
}

@media (max-width: 560px) {
  .brand-tagline { display: none; }
  .brand-name { font-size: 1rem; }
  .brand-mark { width: 2.4rem; height: 2.4rem; }
}

.site-footer {
  position: relative;
  background: var(--color-space-deep);
  color: var(--color-muted);
  border-top: 1px solid rgba(0, 212, 255, 0.14);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.5;
  background-image:
    radial-gradient(1px 1px at 12% 18%, rgba(255, 255, 255, 0.65), transparent 1px),
    radial-gradient(1px 1px at 38% 62%, rgba(0, 212, 255, 0.7), transparent 1px),
    radial-gradient(2px 2px at 72% 30%, rgba(255, 255, 255, 0.45), transparent 2px),
    radial-gradient(1px 1px at 88% 80%, rgba(155, 89, 182, 0.8), transparent 1px);
}

.site-footer::after {
  content: "";
  position: absolute;
  right: -8rem;
  bottom: -8rem;
  width: 18rem;
  height: 18rem;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(155, 89, 182, 0.22), transparent 65%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  z-index: 1;
  max-width: 75rem;
  margin-inline: auto;
  padding: clamp(3rem, 6vw, 5rem) clamp(1.25rem, 4vw, 2.5rem) 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.6fr);
  gap: clamp(1.5rem, 4vw, 3rem);
}

.footer-brand-pane {
  display: grid;
  align-content: start;
  gap: 1.25rem;
}

.brand--footer .brand-name {
  font-size: 1.4rem;
  color: var(--color-white);
}

.brand--footer .brand-tagline {
  color: var(--color-electric);
}

.footer-trust {
  max-width: 24rem;
  padding-left: 1rem;
  border-left: 2px solid rgba(0, 212, 255, 0.4);
  color: var(--color-muted);
  font-size: 0.95rem;
}

.footer-col {
  display: grid;
  align-content: start;
  gap: 1rem;
}

.footer-heading {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-white);
}

.footer-list {
  display: grid;
  gap: 0.35rem;
}

.footer-list a,
.footer-legal a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

.footer-list a:hover,
.footer-legal a:hover {
  color: var(--color-white);
}

.contact-line {
  display: grid;
  gap: 0.2rem;
  margin-bottom: 1rem;
}

.contact-label {
  font-family: var(--font-heading);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-purple);
}

.contact-value {
  color: var(--color-muted);
  font-size: 0.95rem;
  overflow-wrap: anywhere;
}

a.contact-value:hover {
  color: var(--color-white);
}

.footer-rule {
  margin: 2.5rem 0 1rem;
  border: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  color: var(--color-muted);
  font-size: 0.85rem;
}

.footer-copyright,
.footer-icp {
  color: rgba(245, 247, 250, 0.6);
}

.footer-icp {
  font-family: var(--font-heading);
  letter-spacing: 0.06em;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}

@media (max-width: 960px) {
  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-brand-pane {
    grid-column: 1 / -1;
  }
}

@media (max-width: 600px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

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

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin: 0 0 2rem;
  padding: 0;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.breadcrumb-item a {
  color: var(--color-muted);
  text-decoration: none;
}

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

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 0.75rem;
  color: rgba(255, 255, 255, 0.3);
}

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

.section-panel {
  position: relative;
  padding-block: var(--section-space);
}

.section-panel + .section-panel {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.chapter {
  display: grid;
  grid-template-columns: minmax(4rem, 7rem) 1fr;
  gap: clamp(1rem, 3vw, 2.5rem);
  align-items: start;
}

.chapter-number {
  font-family: var(--font-heading);
  font-size: clamp(3rem, 7vw, 5rem);
  font-weight: 800;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px rgba(0, 212, 255, 0.55);
}

.chapter-content {
  min-width: 0;
}

.section-heading {
  margin-bottom: 2.5rem;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.8rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-electric);
}

.section-kicker::before {
  content: "";
  width: 2rem;
  height: 1px;
  background: var(--color-electric);
}

.section-title {
  margin-top: 0.5rem;
  font-size: clamp(2rem, 4.5vw, 3.75rem);
  color: var(--color-white);
}

.section-lead {
  max-width: 46rem;
  margin-top: 1rem;
  color: var(--color-muted);
}

[data-scheme="light"] {
  background: var(--color-light);
  color: var(--color-ink);
}

[data-scheme="light"] .section-title { color: var(--color-ink); }

[data-scheme="light"] .section-lead { color: var(--color-grey); }

[data-scheme="light"] .section-kicker { color: var(--color-purple); }

[data-scheme="light"] .section-kicker::before { background: var(--color-purple); }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.card {
  position: relative;
  display: grid;
  gap: 1rem;
  padding: 1.5rem;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.02));
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  border-color: rgba(0, 212, 255, 0.3);
  transform: translateY(-2px);
}

.card--light {
  background: var(--color-white);
  border-color: #E5E7EB;
  color: var(--color-grey);
  box-shadow: 0 0.5rem 1.5rem rgba(17, 24, 39, 0.08);
}

.card--light .card-title { color: var(--color-ink); }

.card-title {
  color: var(--color-white);
  font-size: 1.2rem;
}

.card-copy {
  color: var(--color-muted);
  font-size: 0.95rem;
}

.card--light .card-copy { color: var(--color-grey); }

.card-meta {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  color: var(--color-electric);
}

@media (max-width: 960px) {
  .card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .card-grid { grid-template-columns: minmax(0, 1fr); }
}

.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: #0F2145;
  border: 1px solid rgba(0, 212, 255, 0.14);
  border-radius: 0.5rem;
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.12), transparent 45%);
}

.media-ratio-16x9 { aspect-ratio: 16 / 9; }

.media-ratio-4x3 { aspect-ratio: 4 / 3; }

.media-ratio-1x1 { aspect-ratio: 1 / 1; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.75rem 1.4rem;
  border: 1px solid transparent;
  border-radius: 0.375rem;
  background: transparent;
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.25s ease, border-color 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-orange), #FF8B58);
  border-color: rgba(255, 255, 255, 0.2);
  color: var(--color-space);
  box-shadow: 0 0.5rem 1.25rem rgba(255, 107, 53, 0.28);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
}

.btn-primary:hover {
  background: linear-gradient(135deg, #FF5A1F, var(--color-orange));
  color: var(--color-space);
  transform: translateY(-2px);
  box-shadow: 0 0.75rem 2rem rgba(255, 107, 53, 0.4);
}

.btn-quiet {
  background: rgba(0, 212, 255, 0.08);
  border-color: rgba(0, 212, 255, 0.35);
  color: var(--color-electric);
}

.btn-quiet:hover {
  background: rgba(0, 212, 255, 0.18);
  color: var(--color-white);
}

.btn-block {
  width: 100%;
}

@media (prefers-reduced-motion: reduce) {
  .btn:hover,
  .card:hover {
    transform: none;
  }
}

.data-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.25rem 0.65rem;
  border: 1px solid rgba(0, 212, 255, 0.35);
  border-radius: 999px;
  background: rgba(0, 212, 255, 0.08);
  color: var(--color-electric);
  font-family: var(--font-heading);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
}

.grid {
  display: grid;
  gap: 1.25rem;
}

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

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

.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

@media (max-width: 960px) {
  .grid-3,
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .grid-2,
  .grid-3,
  .grid-4 { grid-template-columns: minmax(0, 1fr); }
}

[data-reveal] {
  transition: opacity 0.6s ease, transform 0.6s ease;
}

html.js [data-reveal]:not([data-revealed="true"]) {
  opacity: 0;
  transform: translateY(1.5rem);
}

@media (prefers-reduced-motion: reduce) {
  [data-reveal] {
    transition: none;
  }

  html.js [data-reveal]:not([data-revealed="true"]) {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .skip-link,
  .site-header,
  .site-nav,
  .nav-toggle-bar,
  .header-cta,
  .card,
  .btn {
    transition: none;
  }
}