:root {
  --bg: #0B1D3A;
  --panel: #0F2547;
  --line: #1C3A6E;
  --line-strong: #2C4F8F;
  --gold: #F2A900;
  --gold-light: #FFC75F;
  --violet: #7B2CBF;
  --violet-mist: #B57BFF;
  --text: #F5F9FF;
  --dim: #AFC2D9;
  --font-display: "Playfair Display", "Noto Serif SC", "Songti SC", "STSong", serif;
  --font-body: Inter, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-pill: 999px;
  --content-max: 1200px;
  --shadow-panel: 0 14px 40px rgba(3, 10, 24, 0.45);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(1100px 520px at 88% -8%, rgba(181, 123, 255, 0.16), transparent 62%),
    radial-gradient(900px 440px at -10% 108%, rgba(44, 79, 143, 0.34), transparent 60%),
    linear-gradient(rgba(28, 58, 110, 0.45) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 58, 110, 0.45) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 34px 34px, 34px 34px;
  background-attachment: fixed;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.18;
  margin: 0 0 0.5em;
  color: var(--text);
}

h1 { font-size: clamp(2.2rem, 5vw, 4rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.2rem); }
h3 { font-size: 1.25rem; }

p {
  margin: 0 0 1em;
}

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.16s ease;
}

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

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

button {
  font: inherit;
}

::selection {
  background: var(--gold);
  color: var(--bg);
}

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
  border-radius: 4px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 300;
  display: inline-block;
  padding: 10px 18px;
  border-radius: var(--radius-pill);
  background: var(--gold);
  color: var(--bg);
  font-weight: 700;
  transform: translateY(-160%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: none;
  outline: 3px solid var(--violet-mist);
  outline-offset: 3px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: rgba(11, 29, 58, 0.88);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  z-index: 5;
  background: linear-gradient(90deg, var(--gold), var(--violet-mist));
  pointer-events: none;
}

.header-inner {
  position: relative;
  max-width: var(--content-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gold);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  box-shadow: 0 0 0 1px var(--gold-light), 0 0 24px rgba(242, 169, 0, 0.35);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-text strong {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text);
}

.brand-text small {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--dim);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-list a {
  display: block;
  position: relative;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.93rem;
  font-weight: 500;
  color: var(--dim);
  transition: color 0.16s ease, background 0.16s ease;
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 50%;
  right: 50%;
  bottom: 2px;
  height: 2px;
  border-radius: 2px;
  background: var(--gold);
  transition: left 0.18s ease, right 0.18s ease;
}

.nav-list a:hover {
  color: var(--text);
  background: rgba(44, 79, 143, 0.22);
}

.nav-list a:hover::after {
  left: 16px;
  right: 16px;
}

.nav-list a[aria-current="page"] {
  color: var(--gold);
  background: rgba(242, 169, 0, 0.1);
}

.nav-list a[aria-current="page"]::after {
  left: 16px;
  right: 16px;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  border: 1px solid var(--gold);
  border-radius: var(--radius-pill);
  color: var(--gold);
  background: transparent;
  font-size: 0.92rem;
  font-weight: 700;
  white-space: nowrap;
  transition: background 0.18s ease, color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.nav-cta:hover {
  background: var(--gold);
  color: var(--bg);
  box-shadow: 0 4px 24px rgba(242, 169, 0, 0.35);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border: 1px solid var(--line-strong);
  border-radius: 12px;
  background: transparent;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.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);
}

.site-footer {
  margin-top: 80px;
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, var(--bg) 0%, #071329 100%);
  color: var(--dim);
}

.footer-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.3fr;
  gap: 40px;
  padding: 56px 24px 40px;
}

.footer-col h2,
.footer-col .footer-heading {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.04em;
  margin: 0 0 16px;
}

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

.footer-logo .brand-mark {
  width: 38px;
  height: 38px;
  font-size: 0.78rem;
  box-shadow: 0 0 0 1px rgba(242, 169, 0, 0.4), 0 0 16px rgba(242, 169, 0, 0.22);
}

.footer-desc {
  font-size: 0.92rem;
  line-height: 1.8;
  margin: 0 0 18px;
  max-width: 34em;
}

.footer-icp {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--dim);
}

.footer-links li,
.footer-meta li {
  margin-bottom: 8px;
}

.footer-links a,
.footer-meta a {
  color: var(--dim);
  font-size: 0.95rem;
  transition: color 0.16s ease;
}

.footer-links a:hover,
.footer-meta a:hover {
  color: var(--gold-light);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer-contact-item {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--dim);
  margin: 0 0 8px;
}

.footer-bottom {
  max-width: var(--content-max);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 18px 24px 24px;
  border-top: 1px solid var(--line);
}

.footer-note {
  font-size: 0.85rem;
  color: var(--dim);
  margin: 0;
  max-width: 42em;
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--dim);
  margin: 0;
  white-space: nowrap;
}

.container {
  width: min(100% - 48px, var(--content-max));
  margin-inline: auto;
}

.section {
  padding-block: clamp(40px, 8vw, 88px);
}

.section-tight {
  padding-block: clamp(24px, 4vw, 44px);
}

.section-alt {
  background: linear-gradient(180deg, rgba(15, 37, 71, 0.65), rgba(15, 37, 71, 0.35));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--line) 0%, var(--line-strong) 45%, transparent 100%);
  margin: 0;
}

.page-hero {
  padding: clamp(48px, 8vw, 88px) 0 32px;
}

.page-title {
  margin-bottom: 0.3em;
}

.page-intro {
  font-size: 1.05rem;
  color: var(--dim);
  max-width: 34em;
  margin-bottom: 0;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--dim);
  margin: 0 0 36px;
}

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

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

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

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

.prose {
  max-width: 72ch;
  font-size: 1.02rem;
  line-height: 1.8;
  color: var(--text);
}

.prose h2 {
  margin-top: 1.8em;
}

.prose p {
  margin: 1em 0;
}

.prose ul {
  list-style: disc;
  padding-left: 1.4em;
  margin: 1em 0;
}

.prose a {
  color: var(--gold);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.mono-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dim);
  margin: 0 0 16px;
}

.mono-label::before {
  content: "";
  width: 20px;
  height: 1px;
  background: var(--gold);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1;
  padding: 14px 28px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.btn-gold {
  background: var(--gold);
  color: var(--bg);
  box-shadow: 0 4px 20px rgba(242, 169, 0, 0.25);
}

.btn-gold:hover {
  background: var(--gold-light);
  color: var(--bg);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(242, 169, 0, 0.32);
}

.btn-ghost {
  border-color: var(--line-strong);
  color: var(--text);
  background: transparent;
}

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

.btn-block {
  width: 100%;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid transparent;
}

.pill-gold {
  background: rgba(242, 169, 0, 0.14);
  color: var(--gold-light);
  border-color: rgba(242, 169, 0, 0.4);
}

.pill-violet {
  background: rgba(123, 44, 191, 0.26);
  color: var(--violet-mist);
  border-color: rgba(123, 44, 191, 0.55);
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.panel-hover {
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.panel-hover:hover {
  transform: translateY(-6px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-panel);
}

.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  background: linear-gradient(135deg, var(--panel), var(--bg));
  aspect-ratio: 16 / 9;
}

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

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

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(rgba(28, 58, 110, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 58, 110, 0.16) 1px, transparent 1px);
  background-size: 22px 22px;
}

.media-placeholder {
  display: grid;
  place-items: center;
  text-align: center;
  padding: 24px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  color: var(--dim);
}

.tabs {
  margin-bottom: 24px;
}

.tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  width: fit-content;
  max-width: 100%;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--panel);
}

.tab-button {
  border: 0;
  background: transparent;
  color: var(--dim);
  font-size: 0.92rem;
  font-weight: 600;
  padding: 9px 22px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: background 0.16s ease, color 0.16s ease;
}

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

.tab-button[aria-selected="true"] {
  background: var(--gold);
  color: var(--bg);
}

.tab-panel[hidden] {
  display: none;
}

.tab-panel:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 8px;
}

details {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 18px 22px;
}

details + details {
  margin-top: 10px;
}

summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--text);
  font-size: 0.98rem;
}

summary:hover {
  color: var(--gold-light);
}

html[data-js] [data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@media (min-width: 981px) and (max-width: 1150px) {
  .nav-list a {
    padding: 8px 10px;
    font-size: 0.88rem;
  }

  .nav-cta {
    padding: 8px 14px;
    font-size: 0.85rem;
  }
}

@media (max-width: 1020px) {
  .footer-inner {
    grid-template-columns: 1.4fr 1fr;
  }
}

@media (max-width: 980px) {
  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 8px);
    left: 16px;
    right: 16px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding: 20px;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: var(--panel);
    box-shadow: 0 16px 48px rgba(3, 10, 24, 0.55);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
    pointer-events: none;
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
  }

  .nav-list a {
    padding: 12px 16px;
    font-size: 1.02rem;
  }

  .nav-list a::after {
    left: 16px;
    right: 16px;
  }

  .nav-cta {
    justify-content: center;
    width: 100%;
    padding: 12px 20px;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 32px, var(--content-max));
  }

  .header-inner {
    padding: 12px 16px;
  }

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

  .brand-text small {
    letter-spacing: 0.2em;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
    font-size: 0.8rem;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 20px 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 20px 20px;
  }

  .tab-list {
    width: 100%;
  }

  .tab-button {
    flex: 1 1 auto;
    text-align: center;
  }
}

@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;
  }

  html[data-js] [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .scroll-progress {
    transition: none;
  }
}