:root {
  --color-bg: #0a0f1e;
  --color-panel: #111827;
  --color-glass: rgba(255, 255, 255, 0.08);
  --color-teal: #0b3c49;
  --color-purple: #3b2d6e;
  --color-wine: #6e2c3a;
  --color-cyan: #00d4ff;
  --color-orange: #ff6b35;
  --color-text: #f5f7fa;
  --color-text-dim: #8a94a6;
  --font-main: "Noto Sans SC", "PingFang SC", sans-serif;
  --font-accent: "JetBrains Mono", "SF Mono", "Cascadia Mono", monospace;
  --header-width: 280px;
  --radius: 14px;
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: var(--font-main);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image:
    radial-gradient(circle at 85% 10%, rgba(59, 45, 110, 0.45), transparent 50%),
    linear-gradient(rgba(0, 212, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.035) 1px, transparent 1px),
    linear-gradient(160deg, #0a0f1e 0%, #102030 100%);
  background-size: auto, 32px 32px, 32px 32px, auto;
  background-attachment: fixed;
}

h1, h2, h3, h4 {
  font-family: var(--font-main);
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.3;
}

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

a:hover {
  color: inherit;
}

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

ul[class], ol[class] {
  list-style: none;
}

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

:focus-visible {
  outline: 2px solid var(--color-orange);
  outline-offset: 2px;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 12px;
  z-index: 9999;
  background: var(--color-orange);
  color: #0a0f1e;
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 6px;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 12px;
}

.page-shell {
  min-height: 100vh;
  margin-left: var(--header-width);
  padding: 48px 48px 72px;
  max-width: 1440px;
}

.main-content,
main[id="main-content"] {
  min-height: 100vh;
  margin-left: var(--header-width);
}

.section {
  padding: 28px 0;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 16px;
  margin-bottom: 24px;
  padding: 8px 0 12px;
  border-bottom: 1px solid rgba(0, 212, 255, 0.12);
}

.section-head__title {
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.section-head__meta {
  font-family: var(--font-accent);
  font-size: 0.75rem;
  color: var(--color-text-dim);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-accent);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--color-cyan);
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--color-orange);
}

.page-title {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.page-abstract {
  font-size: 1rem;
  color: var(--color-text-dim);
  max-width: 60ch;
  line-height: 1.8;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  font-family: var(--font-accent);
  font-size: 0.75rem;
  color: var(--color-text-dim);
  margin-bottom: 20px;
}

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

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

.breadcrumb__sep {
  opacity: 0.5;
}

.text-link {
  color: var(--color-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.grid--tight {
  gap: 16px;
}

.grid--wide {
  gap: 32px;
}

.card {
  background: linear-gradient(145deg, rgba(17, 24, 39, 0.92), rgba(17, 24, 39, 0.72));
  border: 1px solid rgba(0, 212, 255, 0.14);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-3px);
  border-color: rgba(0, 212, 255, 0.38);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

.card--glass {
  background: var(--color-glass);
  backdrop-filter: blur(6px);
  border-color: rgba(255, 255, 255, 0.1);
}

.card__title {
  font-size: 1.15rem;
  font-weight: 900;
  margin-bottom: 8px;
}

.card__text {
  color: var(--color-text-dim);
  font-size: 0.9rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 6px;
  font-family: var(--font-main);
  font-weight: 700;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.btn--primary {
  background: var(--color-orange);
  color: #0a0f1e;
}

.btn--primary:hover {
  box-shadow: 0 6px 18px rgba(255, 107, 53, 0.4);
  transform: translateY(-1px);
}

.btn--ghost {
  border-color: var(--color-cyan);
  color: var(--color-cyan);
  background: transparent;
}

.btn--ghost:hover {
  background: rgba(0, 212, 255, 0.08);
}

.tag-chip {
  display: inline-block;
  background: rgba(0, 212, 255, 0.12);
  color: var(--color-cyan);
  padding: 4px 10px;
  border-radius: 4px;
  font-family: var(--font-accent);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.meta-line {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-accent);
  font-size: 0.75rem;
  color: var(--color-text-dim);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-cyan);
  flex-shrink: 0;
}

.status-dot--offline {
  background: var(--color-text-dim);
}

.image-frame {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(120deg, var(--color-teal), var(--color-purple));
  min-height: 180px;
}

.image-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255, 255, 255, 0.12), transparent 70%);
  transform: translateX(-100%);
  transition: transform 0.4s ease;
}

.image-frame:hover::after {
  transform: translateX(100%);
}

.image-frame--ratio-wide {
  aspect-ratio: 16 / 9;
}

.site-header {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--header-width);
  z-index: 100;
  display: flex;
  flex-direction: column;
  border-right: 1px solid rgba(0, 212, 255, 0.15);
  background:
    radial-gradient(circle at 30% 0%, rgba(59, 45, 110, 0.7), transparent 55%),
    linear-gradient(rgba(0, 212, 255, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.06) 1px, transparent 1px),
    linear-gradient(180deg, #111827 0%, #0a0f1e 100%);
  background-size: auto, 24px 24px, 24px 24px, auto;
  overflow-y: auto;
  overscroll-behavior: contain;
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: linear-gradient(180deg, var(--color-cyan), var(--color-purple), var(--color-orange));
  opacity: 0.8;
  z-index: 2;
  pointer-events: none;
}

.site-header__bar {
  position: relative;
  padding-bottom: 8px;
}

.brand-lockup {
  display: block;
  padding: 28px 20px 16px;
  color: var(--color-text);
}

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

.brand-lockup__name {
  display: block;
  font-size: 1.55rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  line-height: 1.2;
}

.brand-lockup__badge,
.site-footer__badge {
  display: inline-block;
  vertical-align: middle;
  margin-left: 8px;
  background: var(--color-orange);
  color: #0a0f1e;
  font-family: var(--font-accent);
  font-size: 0.62rem;
  font-weight: 700;
  line-height: 1.2;
  padding: 2px 6px;
  border-radius: 4px;
  letter-spacing: 0.08em;
}

.brand-lockup__domain {
  display: block;
  margin-top: 6px;
  font-family: var(--font-accent);
  font-size: 0.7rem;
  color: var(--color-text-dim);
  letter-spacing: 0.04em;
}

.brand-lockup__tagline {
  display: block;
  margin-top: 10px;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-cyan);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-cyan), var(--color-orange));
  transform: scaleX(0);
  transform-origin: 0 50%;
  z-index: 200;
  pointer-events: none;
}

.site-nav {
  flex: 1;
  padding: 8px 12px;
}

.site-nav__intro {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 12px 12px;
  font-family: var(--font-accent);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--color-text-dim);
}

.site-nav__intro-hint {
  color: var(--color-orange);
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-nav__link {
  display: grid;
  grid-template-columns: 32px 1fr auto;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 6px;
  color: var(--color-text);
  position: relative;
  transition: background var(--transition), color var(--transition);
}

.site-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12%;
  bottom: 12%;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background: var(--color-orange);
  opacity: 0;
  transform: scaleY(0.4);
  transition: opacity var(--transition), transform var(--transition);
}

.site-nav__link:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
}

.site-nav__link[aria-current="page"] {
  background: rgba(0, 212, 255, 0.08);
  color: #ffffff;
}

.site-nav__link[aria-current="page"]::before {
  opacity: 1;
  transform: scaleY(1);
}

.site-nav__index {
  font-family: var(--font-accent);
  font-size: 0.7rem;
  color: var(--color-text-dim);
}

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--color-cyan);
}

.site-nav__label {
  font-weight: 700;
  font-size: 0.95rem;
}

.site-nav__en {
  font-family: var(--font-accent);
  font-size: 0.65rem;
  color: var(--color-text-dim);
  letter-spacing: 0.1em;
}

.site-nav__link:hover .site-nav__en {
  color: var(--color-cyan);
}

.site-header__foot {
  margin-top: auto;
  padding: 16px 20px 20px;
  border-top: 1px solid rgba(0, 212, 255, 0.12);
}

.site-header__foot-text {
  font-family: var(--font-accent);
  font-size: 0.7rem;
  color: var(--color-text-dim);
  line-height: 1.65;
}

.nav-toggle {
  display: none;
}

.site-footer {
  margin-left: var(--header-width);
  position: relative;
  background:
    linear-gradient(rgba(0, 212, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.04) 1px, transparent 1px),
    linear-gradient(180deg, #0b3c49 0%, #0a0f1e 60%);
  background-size: 32px 32px, 32px 32px, auto;
  border-top: 1px solid rgba(0, 212, 255, 0.15);
  color: var(--color-text);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 260px;
  background: linear-gradient(90deg, var(--color-orange), var(--color-cyan));
  z-index: 1;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding: 56px 48px 40px;
  max-width: 1440px;
}

.site-footer__name {
  font-size: 1.3rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.site-footer__domain {
  margin-top: 4px;
  font-family: var(--font-accent);
  font-size: 0.7rem;
  color: var(--color-text-dim);
}

.site-footer__desc {
  margin-top: 14px;
  font-size: 0.85rem;
  color: var(--color-text-dim);
  line-height: 1.8;
  max-width: 42ch;
}

.site-footer__heading {
  font-family: var(--font-accent);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--color-cyan);
  margin-bottom: 14px;
}

.footer-link-list,
.footer-meta-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-link-list a {
  color: var(--color-text);
  font-size: 0.9rem;
}

.footer-link-list a:hover {
  color: var(--color-orange);
}

.footer-meta-list {
  color: var(--color-text-dim);
  font-size: 0.85rem;
  line-height: 1.7;
}

.site-footer__note {
  font-size: 0.8rem;
  color: var(--color-text-dim);
  line-height: 1.8;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 20px 48px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  font-family: var(--font-accent);
  font-size: 0.7rem;
  color: var(--color-text-dim);
}

.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 300;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  background: rgba(17, 24, 39, 0.85);
  border: 1px solid rgba(0, 212, 255, 0.35);
  border-radius: 8px;
  color: var(--color-text);
  font-size: 0.75rem;
  font-weight: 700;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
}

.back-top:hover {
  border-color: var(--color-orange);
  background: rgba(17, 24, 39, 0.95);
  transform: translateY(-2px);
}

.back-top__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--color-orange);
  color: #0a0f1e;
  border-radius: 4px;
  font-family: var(--font-accent);
  line-height: 1;
}

.back-top__text {
  font-size: 0.75rem;
}

@media (max-width: 1080px) {
  :root {
    --header-width: 220px;
  }

  .site-header__bar {
    padding-bottom: 4px;
  }

  .brand-lockup {
    padding: 20px 16px 12px;
  }

  .brand-lockup__name {
    font-size: 1.3rem;
  }

  .site-nav {
    padding: 6px 8px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    padding: 48px 32px 32px;
  }

  .site-footer__bottom {
    padding: 16px 32px;
  }
}

@media (max-width: 767px) {
  body {
    background-attachment: scroll;
  }

  .page-shell {
    margin-left: 0;
    padding: 72px 18px 48px;
  }

  .main-content,
  main[id="main-content"] {
    margin-left: 0;
  }

  .site-header {
    inset: 0 0 auto 0;
    width: auto;
    height: auto;
    max-height: 100vh;
    overflow-y: auto;
    display: block;
    border-right: none;
    border-bottom: 1px solid rgba(0, 212, 255, 0.15);
    background: rgba(10, 15, 30, 0.94);
  }

  .site-header__bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
  }

  .brand-lockup {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 0;
  }

  .brand-lockup__name {
    font-size: 1.1rem;
  }

  .brand-lockup__domain {
    margin: 0;
    font-size: 0.6rem;
  }

  .brand-lockup__tagline {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    width: 40px;
    height: 40px;
    border: 1px solid rgba(0, 212, 255, 0.3);
    border-radius: 6px;
  }

  .nav-toggle__bar {
    width: 18px;
    height: 2px;
    background: var(--color-text);
    transition: transform var(--transition), opacity var(--transition);
  }

  .site-header[data-open] .nav-toggle__bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .site-header[data-open] .nav-toggle__bar:nth-child(2) {
    opacity: 0;
  }

  .site-header[data-open] .nav-toggle__bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .site-nav {
    max-height: 0;
    overflow: hidden;
    padding: 0;
    transition: max-height 0.25s ease, padding 0.25s ease;
  }

  .site-header[data-open] .site-nav {
    max-height: 65vh;
    overflow-y: auto;
    padding: 8px 12px 16px;
  }

  .site-header__foot {
    display: none;
  }

  .site-footer {
    margin-left: 0;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 20px 28px;
  }

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

  .back-top {
    right: 16px;
    bottom: 16px;
  }

  .back-top__text {
    display: none;
  }

  .back-top {
    width: 44px;
    height: 44px;
    padding: 0;
    justify-content: 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;
  }

  .back-top {
    transform: none;
  }
}