:root {
  --color-bg: #0A1A2F;
  --color-bg-elev: #122A4D;
  --color-bg-deep: #050D1A;
  --color-neon: #39FF14;
  --color-neon-dim: #1FA836;
  --color-silver: #A8B2C1;
  --color-silver-bright: #D9E0EA;
  --color-orange: #E67E22;
  --neon-rgb: 57,255,20;
  --silver-rgb: 168,178,193;
  --font-head: "Noto Sans CJK SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --space: 8px;
  --header-height: 68px;
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--color-bg);
  background-image:
    linear-gradient(rgba(var(--neon-rgb), 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(var(--neon-rgb), 0.05) 1px, transparent 1px);
  background-size: 52px 52px;
  color: var(--color-silver-bright);
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-head);
  font-weight: 900;
  line-height: 1.15;
  margin: 0 0 0.5em;
}

p {
  margin: 0 0 1em;
}

a {
  color: var(--color-neon);
}

button {
  font: inherit;
}

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

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

:focus-visible {
  outline: 3px solid var(--color-neon);
  outline-offset: 3px;
}

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

#main-content {
  scroll-margin-top: calc(var(--header-height) + 18px);
}

.container {
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: calc(var(--space) * 3);
}

.section {
  padding-block: calc(var(--space) * 9);
}

.section--tight {
  padding-block: calc(var(--space) * 4);
}

.section--dim {
  background: rgba(5, 13, 26, 0.45);
  border-block: 1px solid rgba(var(--silver-rgb), 0.16);
}

.heading-group {
  display: flex;
  gap: calc(var(--space) * 3);
  align-items: flex-start;
}

.heading-group .rotate-label {
  margin-top: 14px;
}

.rotate-label {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--color-silver);
  text-transform: uppercase;
}

.index-label {
  display: inline-flex;
  align-items: center;
  gap: calc(var(--space) * 1);
  color: var(--color-neon);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: calc(var(--space) * 2);
}

.index-label::before {
  content: "[";
  opacity: 0.7;
}

.index-label::after {
  content: "]";
  opacity: 0.7;
}

.index-title {
  font-family: var(--font-head);
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.05;
  font-weight: 900;
  margin: 0;
  letter-spacing: -0.02em;
}

.page-lead {
  max-width: 58ch;
  color: var(--color-silver);
  font-size: 16px;
  line-height: 1.9;
}

.prose {
  font-size: 15px;
  line-height: 1.9;
}

.prose a {
  color: var(--color-neon);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--space) * 1.5);
  list-style: none;
  margin: 0 0 calc(var(--space) * 5);
  padding: 0;
  font-size: 12px;
  color: var(--color-silver);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: calc(var(--space) * 1.5);
}

.breadcrumb__item::after {
  content: "/";
  color: var(--color-neon);
}

.breadcrumb__item:last-child::after {
  display: none;
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: calc(var(--space) * 1.5);
  min-height: 46px;
  padding: 0 calc(var(--space) * 4);
  border: 2px solid var(--color-silver);
  background: transparent;
  color: var(--color-silver-bright);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 4px 4px 0 rgba(var(--neon-rgb), 0.14);
  transition: border-color 0.2s, color 0.2s, background 0.2s, box-shadow 0.2s, transform 0.2s;
}

.btn:hover {
  border-color: var(--color-neon);
  color: var(--color-neon);
  box-shadow: 6px 6px 0 rgba(var(--neon-rgb), 0.2);
  transform: translate(-2px, -2px);
}

.btn--primary {
  background: var(--color-neon);
  border-color: var(--color-neon);
  color: var(--color-bg-deep);
  font-weight: 900;
}

.btn--primary:hover {
  background: var(--color-neon-dim);
  border-color: var(--color-neon-dim);
  color: var(--color-bg-deep);
}

.btn--ghost {
  border-color: var(--color-neon);
  color: var(--color-neon);
  background: rgba(var(--neon-rgb), 0.06);
}

.btn--orange {
  background: var(--color-orange);
  border-color: var(--color-orange);
  color: var(--color-bg-deep);
  font-weight: 900;
}

.btn--orange:hover {
  background: transparent;
  color: var(--color-orange);
  border-color: var(--color-orange);
}

.panel {
  background: var(--color-bg-elev);
  border: 2px solid rgba(var(--silver-rgb), 0.22);
  padding: calc(var(--space) * 4);
  box-shadow: 8px 8px 0 rgba(var(--neon-rgb), 0.08);
}

.panel--glow {
  border-color: rgba(var(--neon-rgb), 0.5);
  box-shadow: 8px 8px 0 rgba(var(--neon-rgb), 0.16);
}

.panel--cut {
  clip-path: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
}

.data-card {
  background: var(--color-bg-elev);
  border-left: 4px solid var(--color-neon);
  padding: calc(var(--space) * 3);
  border-top: 1px solid rgba(var(--silver-rgb), 0.2);
  border-right: 1px solid rgba(var(--silver-rgb), 0.2);
  border-bottom: 1px solid rgba(var(--silver-rgb), 0.2);
}

.data-card--warn {
  border-left-color: var(--color-orange);
}

.data-card--warn .data-card__value {
  color: var(--color-orange);
}

.data-card__label {
  font-size: 12px;
  color: var(--color-silver);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.data-card__value {
  font-family: var(--font-head);
  font-size: 32px;
  font-weight: 900;
  color: var(--color-silver-bright);
  line-height: 1.1;
  margin-top: calc(var(--space) * 1.5);
}

.chapter-preview {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: calc(var(--space) * 4);
}

.chapter-preview__item {
  display: block;
  padding: calc(var(--space) * 4);
  background: var(--color-bg-elev);
  border: 1px solid rgba(var(--silver-rgb), 0.22);
  min-height: 180px;
  text-decoration: none;
  color: inherit;
  box-shadow: 6px 6px 0 rgba(var(--neon-rgb), 0.08);
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}

.chapter-preview__item:hover {
  border-color: var(--color-neon);
  transform: translate(-2px, -2px);
  box-shadow: 10px 10px 0 rgba(var(--neon-rgb), 0.18);
}

.chapter-preview__index {
  display: block;
  font-size: 12px;
  color: var(--color-neon);
  letter-spacing: 0.1em;
  margin-bottom: calc(var(--space) * 2);
}

.chapter-preview__title {
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 900;
  margin-bottom: calc(var(--space) * 1.5);
}

.chapter-preview__desc {
  font-size: 13px;
  color: var(--color-silver);
}

.data-stream {
  position: relative;
  overflow: hidden;
}

.data-stream::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-neon), transparent);
  animation: dataStream 3s linear infinite;
  pointer-events: none;
}

@keyframes dataStream {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(100%);
  }
}

.media {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  min-height: 180px;
  background: var(--color-bg-elev);
  border: 1px solid rgba(var(--silver-rgb), 0.25);
}

.media::before {
  content: "IMG";
  position: absolute;
  top: 8px;
  right: 10px;
  color: rgba(var(--silver-rgb), 0.5);
  font-size: 10px;
  letter-spacing: 0.15em;
}

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

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

.media__placeholder {
  padding: calc(var(--space) * 3);
  text-align: center;
  font-size: 12px;
  color: var(--color-silver);
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

.accordion {
  border: 1px solid rgba(var(--silver-rgb), 0.2);
  background: rgba(5, 13, 26, 0.4);
}

.accordion__item + .accordion__item {
  border-top: 1px solid rgba(var(--silver-rgb), 0.15);
}

.accordion__trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: calc(var(--space) * 2);
  padding: calc(var(--space) * 2.5) calc(var(--space) * 3);
  background: none;
  border: 0;
  color: var(--color-silver-bright);
  font-weight: 700;
  font-size: 16px;
  text-align: left;
  cursor: pointer;
}

.accordion__trigger::after {
  content: "+";
  color: var(--color-neon);
  font-size: 20px;
  line-height: 1;
}

.accordion__item[data-open] .accordion__trigger::after {
  content: "−";
}

.accordion__panel {
  padding: 0 calc(var(--space) * 3);
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.accordion__panel[data-open] {
  max-height: 800px;
  padding-bottom: calc(var(--space) * 2.5);
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 16px;
  z-index: 500;
  background: var(--color-neon);
  color: var(--color-bg-deep);
  padding: 12px 20px;
  font-weight: 900;
  text-decoration: none;
  font-size: 14px;
}

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

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  z-index: 300;
  background: rgba(var(--silver-rgb), 0.15);
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--color-neon), var(--color-neon-dim));
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 150;
  background: rgba(5, 13, 26, 0.94);
  border-bottom: 1px solid rgba(var(--silver-rgb), 0.2);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.site-header__inner {
  position: relative;
  z-index: 20;
  max-width: 1440px;
  margin-inline: auto;
  min-height: var(--header-height);
  padding-inline: calc(var(--space) * 2.5);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: calc(var(--space) * 2);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--color-silver-bright);
}

.brand__mark {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 26px;
}

.brand__bar {
  width: 5px;
  height: 10px;
  background: var(--color-silver);
  transform: skewX(-25deg);
}

.brand__bar--b {
  height: 18px;
  background: var(--color-neon);
}

.brand__bar--t {
  height: 26px;
  background: var(--color-silver);
}

.brand__name {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 900;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand__prefix {
  font-size: 11px;
  color: var(--color-silver);
  border-left: 1px solid rgba(var(--silver-rgb), 0.3);
  padding-left: 10px;
  letter-spacing: 0.2em;
  white-space: nowrap;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 15;
  padding: calc(var(--header-height) + 24px) 24px 32px;
  background: rgba(5, 13, 26, 0.98);
  border-bottom: 2px solid var(--color-neon);
  transform: translateY(-100%);
  visibility: hidden;
  transition: transform 0.3s ease, visibility 0.3s;
}

.site-nav[data-open] {
  transform: translateY(0);
  visibility: visible;
}

.site-nav__list {
  display: flex;
  flex-direction: column;
  gap: calc(var(--space) * 1.5);
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__item {
  margin: 0;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 12px 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--color-silver);
  text-decoration: none;
  font-family: var(--font-mono);
  text-transform: uppercase;
  border-bottom: 1px solid rgba(var(--silver-rgb), 0.15);
}

.site-nav__link::before {
  content: "[";
  display: inline-block;
  opacity: 0;
  margin-right: 0;
  color: var(--color-neon);
  transition: opacity 0.18s, margin-right 0.18s;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  height: 2px;
  width: 0;
  background: var(--color-neon);
  transition: width 0.22s ease;
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"] {
  color: var(--color-neon);
}

.site-nav__link:hover::before,
.site-nav__link[aria-current="page"]::before {
  opacity: 0.7;
  margin-right: 3px;
}

.site-nav__link:hover::after,
.site-nav__link[aria-current="page"]::after {
  width: 100%;
}

.header-actions {
  position: relative;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: calc(var(--space) * 2);
}

.status-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px 5px 16px;
  border: 1px solid rgba(var(--neon-rgb), 0.4);
  background: rgba(var(--neon-rgb), 0.06);
  color: var(--color-neon);
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  clip-path: polygon(10px 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
}

.status-chip__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-neon);
  box-shadow: 0 0 8px var(--color-neon);
  animation: signalPulse 1.6s infinite;
}

@keyframes signalPulse {
  50% {
    opacity: 0.4;
  }
}

.header-trigger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 46px;
  height: 46px;
  padding: 0;
  background: transparent;
  border: 1px solid rgba(var(--silver-rgb), 0.3);
  cursor: pointer;
}

.header-trigger__line {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-silver-bright);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

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

.header-trigger[aria-expanded="true"] .header-trigger__line:nth-child(2) {
  opacity: 0;
}

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

.back-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 500;
  min-width: 54px;
  height: 54px;
  padding: 8px 10px;
  background: var(--color-neon);
  color: var(--color-bg-deep);
  border: 2px solid var(--color-neon-dim);
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 12px;
  letter-spacing: 0.05em;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 12px 100%, 0 calc(100% - 12px));
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity 0.25s, transform 0.25s, visibility 0.25s;
}

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

.back-top:hover {
  background: var(--color-neon-dim);
  color: var(--color-bg-deep);
}

.site-footer {
  background: var(--color-bg-deep);
  border-top: 2px solid var(--color-neon);
  color: var(--color-silver);
  margin-top: calc(var(--space) * 12);
  position: relative;
}

.site-footer__grid {
  max-width: 1240px;
  margin-inline: auto;
  padding: calc(var(--space) * 7) calc(var(--space) * 3) calc(var(--space) * 5);
  display: grid;
  grid-template-columns: 1.2fr 0.7fr 0.9fr 0.8fr;
  gap: calc(var(--space) * 5);
}

.footer-console {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: calc(var(--space) * 3);
}

.footer-console__brand {
  font-family: var(--font-head);
  font-size: 28px;
  font-weight: 900;
  color: var(--color-silver-bright);
  letter-spacing: 0.05em;
  margin: 0;
}

.footer-console__brand::after {
  content: "_";
  color: var(--color-neon);
}

.footer-console__statement {
  font-size: 13px;
  line-height: 1.9;
  max-width: 34ch;
  margin: 0;
}

.footer-console__code {
  margin: 0;
  color: var(--color-neon);
  font-size: 11px;
  letter-spacing: 0.2em;
}

.footer-heading {
  font-size: 11px;
  letter-spacing: 0.15em;
  color: var(--color-neon);
  margin: 0 0 calc(var(--space) * 3);
  font-family: var(--font-head);
  text-transform: uppercase;
}

.footer-nav__list,
.footer-comms__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: calc(var(--space) * 1.5);
}

.footer-nav__list a {
  display: inline-block;
  padding-left: 0;
  color: var(--color-silver);
  text-decoration: none;
  font-size: 13px;
  transition: color 0.2s, padding-left 0.2s;
}

.footer-nav__list a:hover {
  color: var(--color-neon);
  padding-left: 8px;
}

.footer-comms__list li {
  font-size: 13px;
  line-height: 1.6;
}

.footer-nav--meta {
  border-left: 1px solid rgba(var(--silver-rgb), 0.15);
  padding-left: calc(var(--space) * 3);
}

.site-footer__meta {
  border-top: 1px solid rgba(var(--silver-rgb), 0.2);
  padding-block: calc(var(--space) * 2.5);
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: calc(var(--space) * 3);
  display: flex;
  flex-wrap: wrap;
  gap: calc(var(--space) * 3);
  font-size: 12px;
  color: rgba(var(--silver-rgb), 0.8);
}

.footer-meta__note {
  color: var(--color-orange);
}

@media (min-width: 901px) {
  .site-nav {
    position: static;
    z-index: auto;
    padding: 0;
    border-bottom: 0;
    background: transparent;
    transform: none;
    visibility: visible;
  }

  .site-nav__list {
    flex-direction: row;
    gap: calc(var(--space) * 2);
  }

  .site-nav__link {
    padding: 6px 2px;
    font-size: 13px;
    border-bottom: 0;
  }
}

@media (max-width: 900px) {
  .header-trigger {
    display: inline-flex;
  }

  .status-chip {
    display: none;
  }

  .site-header__inner {
    padding-inline: 16px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .container {
    padding-inline: calc(var(--space) * 2);
  }

  .section {
    padding-block: calc(var(--space) * 5);
  }

  .chapter-preview {
    grid-template-columns: 1fr;
  }

  .heading-group {
    flex-direction: column;
    gap: calc(var(--space) * 2);
  }

  .heading-group .rotate-label {
    writing-mode: horizontal-tb;
    margin-top: 0;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: calc(var(--space) * 4);
    padding-inline: calc(var(--space) * 2);
  }

  .footer-nav--meta {
    border-left: 0;
    padding-left: 0;
  }

  .site-footer__meta {
    flex-direction: column;
    gap: calc(var(--space) * 1.5);
    padding-inline: calc(var(--space) * 2);
  }

  .brand__prefix {
    display: none;
  }

  .back-top {
    right: 12px;
    bottom: 12px;
  }
}

@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;
  }
}