:root {
  --space: #0B1026;
  --nebula: #141B3D;
  --gold: #F5D76E;
  --cyan: #00E5FF;
  --star: #E0E6F0;
  --muted: #8A9BB8;
  --glass: rgba(20, 27, 61, 0.6);
  --orange: #FF9F43;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", STSong, serif;
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container: 1180px;
  --gutter: clamp(1rem, 4vw, 2.5rem);
  --ease: 200ms cubic-bezier(0.2, 0.8, 0.2, 1);
  --scroll-progress: 0%;
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-sans);
  font-weight: 400;
  letter-spacing: 0.02em;
  line-height: 1.7;
  color: var(--star);
  background-color: var(--space);
  background-image:
    radial-gradient(1px 1px at 12% 24%, rgba(224, 230, 240, 0.5), transparent 100%),
    radial-gradient(1px 1px at 38% 70%, rgba(245, 215, 110, 0.36), transparent 100%),
    radial-gradient(1px 1px at 64% 18%, rgba(0, 229, 255, 0.4), transparent 100%),
    radial-gradient(1px 1px at 82% 48%, rgba(224, 230, 240, 0.38), transparent 100%),
    radial-gradient(1px 1px at 92% 80%, rgba(245, 215, 110, 0.25), transparent 100%),
    radial-gradient(900px 500px at 90% -10%, rgba(20, 27, 61, 0.72), transparent 70%),
    radial-gradient(700px 500px at -8% 28%, rgba(0, 229, 255, 0.1), transparent 70%);
  background-attachment: fixed;
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: var(--scroll-progress, 0%);
  height: 2px;
  z-index: 120;
  pointer-events: none;
  background: linear-gradient(90deg, var(--gold), var(--cyan));
  box-shadow: 0 0 12px rgba(0, 229, 255, 0.35);
}

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

a {
  color: var(--cyan);
  text-decoration: underline;
  text-decoration-color: rgba(0, 229, 255, 0.35);
  text-underline-offset: 0.22em;
  transition: color var(--ease), text-decoration-color var(--ease);
}

a:hover {
  color: var(--gold);
  text-decoration-color: rgba(245, 215, 110, 0.55);
}

a.brand,
a.nav-link,
a.footer-link,
a.btn {
  text-decoration: none;
}

h1,
h2,
h3,
h4 {
  margin: 0 0 1rem;
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: 0.05em;
  color: var(--star);
}

h1 {
  font-size: clamp(2.6rem, 6vw, 4.4rem);
}

h2 {
  font-size: clamp(2rem, 5vw, 3.2rem);
}

h3 {
  font-size: clamp(1.25rem, 3vw, 1.6rem);
}

p,
ul,
ol,
dl,
blockquote {
  margin: 0 0 1rem;
}

ul,
ol {
  padding-left: 1.25rem;
}

button {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  cursor: pointer;
}

:focus {
  outline: 2px solid rgba(0, 229, 255, 0.72);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

::selection {
  background: rgba(0, 229, 255, 0.28);
  color: #ffffff;
}

.container,
.section-inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

#main-content {
  flex: 1 0 auto;
  width: 100%;
  outline: none;
  scroll-margin-top: 6.5rem;
}

.skip-link {
  position: fixed;
  top: 0.8rem;
  left: 0.8rem;
  z-index: 130;
  padding: 0.6rem 1rem;
  border: 1px solid var(--gold);
  border-radius: 10px;
  background: rgba(11, 16, 38, 0.96);
  color: var(--gold);
  font-size: 0.85rem;
  transform: translateY(-250%);
  opacity: 0;
  transition: transform var(--ease), opacity var(--ease);
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  flex-shrink: 0;
  background: linear-gradient(180deg, rgba(11, 16, 38, 0.88), rgba(11, 16, 38, 0.72));
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(0, 229, 255, 0.14);
  transition: box-shadow var(--ease), background var(--ease), border-color var(--ease);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 229, 255, 0), rgba(0, 229, 255, 0.5), rgba(245, 215, 110, 0.4), rgba(0, 229, 255, 0));
  opacity: 0.5;
}

.site-header[data-scrolled="true"] {
  background: rgba(11, 16, 38, 0.94);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.28);
  border-bottom-color: rgba(0, 229, 255, 0.24);
}

.topbar {
  background: rgba(20, 27, 61, 0.5);
  border-bottom: 1px solid rgba(245, 215, 110, 0.14);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 2.25rem;
}

.topbar-mark {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin: 0;
  color: var(--gold);
  font-weight: 600;
}

.topbar-note {
  margin: 0;
  color: var(--muted);
}

.star-glyph {
  font-size: 1.1em;
  line-height: 1;
  color: var(--gold);
}

.header-main {
  width: 100%;
}

.header-rail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  padding-top: 0.55rem;
  padding-bottom: 0.55rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  margin-right: auto;
}

.brand-orb {
  width: 1.9rem;
  height: 1.9rem;
  flex: 0 0 auto;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, var(--gold), var(--cyan) 60%, var(--space) 70%);
  box-shadow: 0 0 18px rgba(0, 229, 255, 0.35), 0 0 6px rgba(245, 215, 110, 0.35);
  align-self: center;
}

.brand-name {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--gold);
}

.brand-latin {
  margin-top: 0.12rem;
  align-self: flex-end;
  padding-right: 0.2em;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--cyan);
  line-height: 1.3;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.22rem;
  min-width: 3rem;
  min-height: 2.8rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid rgba(0, 229, 255, 0.25);
  border-radius: 12px;
  background: rgba(20, 27, 61, 0.45);
  color: var(--star);
  transition: border-color var(--ease), color var(--ease), background var(--ease);
}

.nav-toggle:hover,
.nav-toggle[aria-expanded="true"] {
  border-color: var(--gold);
  color: var(--gold);
}

.nav-toggle-line {
  width: 1.15rem;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

.nav-toggle-label {
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  line-height: 1;
  margin-top: 0.1rem;
}

.site-nav {
  flex-basis: 100%;
  order: 4;
  min-height: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  visibility: hidden;
  transition: max-height var(--ease), opacity var(--ease), visibility var(--ease);
}

.site-nav[data-open] {
  max-height: calc(100vh - 130px);
  overflow-y: auto;
  opacity: 1;
  visibility: visible;
  background: rgba(11, 16, 38, 0.9);
  border-top: 1px solid rgba(0, 229, 255, 0.14);
  border-bottom: 1px solid rgba(0, 229, 255, 0.14);
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  margin: 0;
  padding: 0.6rem 0 0.9rem;
  list-style: none;
  border-top: 1px solid rgba(0, 229, 255, 0.14);
}

.site-nav[data-open] .nav-list {
  border-top-color: rgba(245, 215, 110, 0.28);
}

.nav-link {
  position: relative;
  display: block;
  padding: 0.55rem 0.85rem;
  border-radius: 6px;
  font-size: 0.92rem;
  letter-spacing: 0.12em;
  color: var(--star);
  white-space: nowrap;
  transition: color var(--ease), background var(--ease);
}

.nav-link::before {
  content: "";
  position: absolute;
  left: 0.85rem;
  right: 0.85rem;
  bottom: 0.35rem;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--ease);
}

.nav-link:hover {
  color: var(--cyan);
  background: rgba(0, 229, 255, 0.06);
}

.nav-link:hover::before {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--gold);
  background: rgba(245, 215, 110, 0.06);
}

.nav-link[aria-current="page"]::before {
  background: var(--gold);
  transform: scaleX(1);
}

.air-footer {
  position: relative;
  flex-shrink: 0;
  margin-top: auto;
  background: linear-gradient(180deg, rgba(11, 16, 38, 0.94), #0B1026 60%);
  border-top: 1px solid rgba(0, 229, 255, 0.18);
  color: var(--muted);
  overflow: hidden;
}

.air-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(2px 2px at 20% 30%, rgba(245, 215, 110, 0.3), transparent 100%),
    radial-gradient(1px 1px at 75% 60%, rgba(0, 229, 255, 0.25), transparent 100%),
    radial-gradient(1px 1px at 90% 25%, rgba(255, 255, 255, 0.3), transparent 100%);
}

.footer-orbit {
  position: absolute;
  left: 50%;
  bottom: -11rem;
  width: 120%;
  height: 16rem;
  transform: translateX(-50%);
  border: 1px solid rgba(0, 229, 255, 0.1);
  border-radius: 50%;
  pointer-events: none;
}

.footer-orbit::before {
  content: "";
  position: absolute;
  inset: 18% 28%;
  border: 1px solid rgba(0, 229, 255, 0.06);
  border-radius: 50%;
}

.footer-orbit::after {
  content: "";
  position: absolute;
  top: -4px;
  left: 50%;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 14px rgba(245, 215, 110, 0.8);
  transform: translateX(-50%);
}

.footer-shell {
  position: relative;
  z-index: 1;
  padding-top: clamp(3rem, 7vw, 5rem);
  padding-bottom: 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 2.2fr) minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.3fr);
  gap: clamp(1.5rem, 4vw, 3rem);
}

.footer-brand .brand {
  margin-bottom: 1rem;
}

.footer-about {
  max-width: 34ch;
  margin: 0.8rem 0 1rem;
  line-height: 1.7;
  color: var(--muted);
}

.footer-trust {
  max-width: 36ch;
  margin: 0;
  padding-left: 0.75rem;
  border-left: 2px solid rgba(245, 215, 110, 0.5);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.footer-heading {
  margin: 0 0 1rem;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

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

.footer-link {
  display: inline-block;
  padding: 0.22rem 0;
  color: var(--muted);
  transition: color var(--ease), padding-left var(--ease);
}

.footer-link:hover {
  color: var(--cyan);
  padding-left: 0.35rem;
}

.footer-contact-line {
  margin: 0.25rem 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: clamp(2.5rem, 5vw, 4rem);
  padding-top: 1.5rem;
  border-top: 1px solid rgba(139, 155, 184, 0.14);
  color: var(--muted);
  font-size: 0.82rem;
}

.footer-meta {
  margin: 0;
}

.top-btn {
  position: fixed;
  right: clamp(1rem, 4vw, 2.5rem);
  bottom: clamp(1rem, 4vw, 2.5rem);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1rem;
  border: 1px solid rgba(0, 229, 255, 0.32);
  border-radius: 999px;
  background: rgba(11, 16, 38, 0.82);
  color: var(--star);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--ease), transform var(--ease), visibility var(--ease), border-color var(--ease);
}

.top-btn:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.top-btn.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.top-btn-text {
  font-size: 0.85rem;
  letter-spacing: 0.1em;
}

.section {
  position: relative;
  z-index: 0;
  padding: clamp(3.5rem, 9vw, 6.5rem) 0;
}

.section--reduced {
  padding: clamp(2.5rem, 6vw, 4rem) 0;
}

.section-head {
  max-width: 720px;
  margin-bottom: clamp(2rem, 5vw, 3.5rem);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--cyan);
}

.kicker::before {
  content: "";
  width: 1.5rem;
  height: 2px;
  background: var(--cyan);
}

.section-title {
  margin: 0.4rem 0 1rem;
}

.section-lead {
  max-width: 64ch;
  color: var(--muted);
  font-size: 1.05rem;
}

.page-hero {
  position: relative;
  z-index: 0;
  padding: clamp(2.5rem, 8vw, 5.5rem) 0;
}

.hero-title {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4.8rem);
  line-height: 1.1;
  max-width: 14ch;
}

.hero-lead {
  max-width: 56ch;
  margin-top: 1rem;
  color: var(--muted);
  font-size: 1.05rem;
}

.chapter {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 1rem clamp(1rem, 3vw, 2rem);
  align-items: start;
  padding: 1rem 0;
  border-bottom: 1px solid rgba(139, 155, 184, 0.14);
}

.chapter-index {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.6rem;
  height: 2.6rem;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--cyan);
  border: 1px solid rgba(0, 229, 255, 0.28);
  border-radius: 50%;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(1rem, 3vw, 1.5rem);
}

.glass-card {
  position: relative;
  padding: clamp(1.25rem, 3vw, 1.8rem);
  border: 1px solid rgba(0, 229, 255, 0.14);
  border-radius: 24px;
  background: linear-gradient(145deg, rgba(20, 27, 61, 0.72), rgba(11, 16, 38, 0.62));
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.22);
  transition: transform var(--ease), border-color var(--ease), box-shadow var(--ease);
}

.glass-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 229, 255, 0.34);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.3);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: clamp(1rem, 3vw, 1.5rem);
}

.stat-card {
  text-align: left;
}

.stat-value {
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2rem, 6vw, 3.2rem);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.stat-label {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.85rem;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.media-frame {
  position: relative;
  border: 1px solid rgba(0, 229, 255, 0.16);
  border-radius: 20px;
  overflow: hidden;
  background: linear-gradient(145deg, rgba(20, 27, 61, 0.8), rgba(11, 16, 38, 0.95));
}

.media-frame::before {
  content: "";
  display: block;
  padding-bottom: 56.25%;
}

.media-frame--tall::before {
  padding-bottom: 72%;
}

.media-frame > img,
.media-frame > .placeholder,
.media-frame > .media-content {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame > .placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  text-align: center;
  color: var(--muted);
  background:
    radial-gradient(2px 2px at 20% 30%, rgba(245, 215, 110, 0.4), transparent 100%),
    radial-gradient(2px 2px at 70% 60%, rgba(0, 229, 255, 0.3), transparent 100%);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.9rem 1.6rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--ease), border-color var(--ease), color var(--ease), transform var(--ease), box-shadow var(--ease);
}

.btn-primary {
  background: var(--gold);
  border-color: var(--gold);
  color: #0B1026;
}

.btn-primary:hover {
  background: #ffe194;
  border-color: #ffe194;
  color: #0B1026;
  box-shadow: 0 8px 22px rgba(245, 215, 110, 0.22);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(0, 229, 255, 0.4);
  color: var(--cyan);
}

.btn-ghost:hover {
  background: rgba(0, 229, 255, 0.08);
  color: var(--cyan);
  box-shadow: inset 0 0 0 1px rgba(0, 229, 255, 0.4);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
  font-size: 0.85rem;
  color: var(--muted);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.breadcrumb li + li::before {
  content: "/";
  color: rgba(139, 155, 184, 0.5);
}

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

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

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

.star-divider {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin: 2rem 0;
  color: var(--cyan);
}

.star-divider::before,
.star-divider::after {
  content: "";
  height: 1px;
  flex: 1;
  background: linear-gradient(90deg, rgba(20, 27, 61, 0), rgba(0, 229, 255, 0.4));
}

.star-divider::after {
  background: linear-gradient(90deg, rgba(0, 229, 255, 0.4), rgba(20, 27, 61, 0));
}

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

@media (max-width: 700px) {
  .topbar-note {
    display: none;
  }
}

@media (min-width: 861px) {
  .header-rail {
    flex-wrap: nowrap;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    flex-basis: auto;
    order: 0;
    margin-left: auto;
    max-height: none;
    min-height: 0;
    opacity: 1;
    visibility: visible;
    overflow: visible;
    background: transparent;
    border: 0;
    padding: 0;
  }

  .nav-list {
    flex-direction: row;
    align-items: center;
    gap: 0.15rem;
    padding: 0.2rem 0;
    border-top: 0;
  }

  .nav-link {
    padding: 0.6rem 0.72rem;
    font-size: 0.88rem;
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    justify-content: center;
    text-align: center;
  }

  .top-btn-text {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}