:root {
  --space-blue: #0B1B3D;
  --neon-green: #00FFA3;
  --graphite: #1E242E;
  --paper: #F5F1E8;
  --ink: #111827;
  --electric-blue: #3B82F6;
  --mist: #D1D5DB;
  --signal-red: #FF3B30;
  --violet: #8B5CF6;
  --bg: var(--space-blue);
  --fg: var(--paper);
  --link: var(--electric-blue);
  --link-hover: var(--neon-green);
  --font-mono: "JetBrains Mono", "SF Mono", "Cascadia Mono", Consolas, "Liberation Mono", monospace;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --header-h: 72px;
  --radius: 6px;
  --shadow-panel: 8px 8px 0 rgba(0, 0, 0, 0.35);
  --shadow-card: 4px 4px 0 rgba(0, 0, 0, 0.3);
  --tr: 300ms ease;
}

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--fg);
  background-color: var(--space-blue);
  background-image:
    linear-gradient(rgba(0, 255, 163, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 163, 0.03) 1px, transparent 1px);
  background-size: 28px 28px;
  overflow-x: hidden;
}

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

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

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

ul,
ol {
  list-style: none;
}

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

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-mono);
  font-weight: 700;
  line-height: 1.2;
  color: inherit;
}

h1 {
  font-size: clamp(28px, 5vw, 44px);
}

h2 {
  font-size: clamp(22px, 3.5vw, 32px);
}

h3 {
  font-size: clamp(18px, 2.5vw, 24px);
}

h4 {
  font-size: 18px;
}

p {
  margin-bottom: 1em;
}

#main-content {
  flex: 1 0 auto;
  width: 100%;
}

.container {
  width: min(1280px, 92%);
  margin-inline: auto;
}

.container--narrow {
  width: min(880px, 92%);
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 9999;
  padding: 10px 18px;
  background: var(--neon-green);
  color: var(--space-blue);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  border-radius: var(--radius);
  transition: top var(--tr);
}

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

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

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--neon-green), var(--electric-blue));
  pointer-events: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  border: 2px solid currentColor;
  border-radius: var(--radius);
  white-space: nowrap;
  transition:
    transform var(--tr),
    box-shadow var(--tr),
    background-color var(--tr),
    color var(--tr),
    border-color var(--tr);
}

.btn:hover {
  color: var(--space-blue);
  background: var(--neon-green);
  border-color: var(--neon-green);
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.25);
}

.btn--v4 {
  color: var(--neon-green);
  background: transparent;
  border-color: var(--neon-green);
}

.btn--v4:hover {
  background: var(--neon-green);
  color: var(--space-blue);
  transform: translate(-2px, -2px) rotate(-1deg);
  box-shadow: 4px 4px 0 rgba(0, 255, 163, 0.2);
}

.btn__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  animation: pulse 2s ease-in-out infinite;
}

.btn__text {
  display: inline-block;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(0.8);
  }
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--space-blue);
  border-bottom: 2px solid var(--neon-green);
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 255, 163, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 163, 0.07) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: 16px;
  width: min(1440px, 94%);
  margin-inline: auto;
  min-height: var(--header-h);
  padding: 10px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--paper);
  font-family: var(--font-mono);
  margin-right: auto;
}

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

.brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: var(--neon-green);
  color: var(--space-blue);
  font-weight: 800;
  font-size: 20px;
  border-radius: 4px;
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.4);
  transition: transform var(--tr), box-shadow var(--tr);
}

.brand:hover .brand__mark {
  transform: rotate(-8deg) scale(1.04);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.5);
}

.brand__text {
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.brand__sub {
  font-size: 12px;
  color: var(--mist);
  margin-left: 2px;
  font-weight: 400;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.nav__link {
  display: block;
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  color: var(--mist);
  letter-spacing: 0.03em;
  line-height: 1.2;
  border: 2px solid transparent;
  border-radius: var(--radius);
  transition:
    color var(--tr),
    background-color var(--tr),
    border-color var(--tr),
    box-shadow var(--tr);
}

.nav__link:hover {
  color: var(--neon-green);
  background: rgba(0, 255, 163, 0.08);
  border-color: rgba(0, 255, 163, 0.4);
}

.nav__link[aria-current="page"] {
  color: var(--space-blue);
  background: var(--neon-green);
  border-color: var(--neon-green);
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.35);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 8px 10px;
  border: 2px solid var(--neon-green);
  border-radius: var(--radius);
  background: transparent;
  transition: background-color var(--tr), transform var(--tr);
}

.nav-toggle:hover {
  background: rgba(0, 255, 163, 0.08);
}

.nav-toggle__line {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--neon-green);
  transition: transform var(--tr), opacity var(--tr);
}

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

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

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

.site-footer {
  position: relative;
  margin-top: 80px;
  background-color: var(--graphite);
  color: var(--mist);
  border-top: 4px solid var(--neon-green);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 255, 163, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 163, 0.04) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

.site-footer__inner {
  position: relative;
  width: min(1280px, 92%);
  margin-inline: auto;
  padding: 64px 0 24px;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 48px;
}

.site-footer__col {
  display: flex;
  flex-direction: column;
}

.site-footer__col--brand {
  gap: 16px;
}

.site-footer .brand {
  color: var(--paper);
}

.site-footer .brand:hover {
  color: var(--paper);
}

.site-footer__trust {
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 280px;
}

.site-footer__heading {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--neon-green);
  padding-bottom: 10px;
  margin-bottom: 18px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.site-footer__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__list a {
  color: var(--mist);
  font-size: 14px;
  transition: color var(--tr), padding-left var(--tr);
}

.site-footer__list a:hover {
  color: var(--neon-green);
  padding-left: 4px;
}

.site-footer__contact {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.site-footer__contact li {
  font-size: 14px;
  line-height: 1.5;
  color: var(--mist);
  overflow-wrap: break-word;
}

.contact__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--neon-green);
  opacity: 0.75;
  margin-bottom: 2px;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  margin-top: 48px;
  padding-top: 24px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
}

.site-footer__icp {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.site-footer__copyright {
  font-family: var(--font-mono);
}

[data-year] {
  font-variant-numeric: tabular-nums;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mist);
  padding: 12px 0;
  margin-bottom: 8px;
}

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

.breadcrumb a:hover {
  color: var(--paper);
  text-decoration: underline;
}

.breadcrumb__separator {
  color: rgba(255, 255, 255, 0.3);
}

.page-head {
  padding: 48px 0 24px;
  margin-bottom: 32px;
  border-bottom: 2px solid rgba(0, 255, 163, 0.25);
}

.page-head__title {
  font-size: clamp(28px, 5vw, 46px);
  color: var(--neon-green);
  text-shadow: 0 2px 0 rgba(0, 0, 0, 0.3);
}

.page-head__desc {
  margin-top: 12px;
  max-width: 680px;
  font-size: 17px;
  color: var(--mist);
}

.panel {
  position: relative;
  background: var(--paper);
  color: var(--ink);
  border: 2px solid var(--ink);
  border-radius: 2px 18px 2px 18px;
  padding: clamp(24px, 4vw, 48px);
  box-shadow: var(--shadow-panel);
  margin-bottom: 32px;
}

.panel h1,
.panel h2,
.panel h3,
.panel h4 {
  color: var(--ink);
}

.panel a {
  color: var(--electric-blue);
}

.panel a:hover {
  color: var(--space-blue);
  text-decoration: underline;
}

.panel--dark {
  background: var(--graphite);
  color: var(--paper);
  border-color: var(--space-blue);
  border-radius: 18px 2px 18px 2px;
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.5);
}

.panel--dark h1,
.panel--dark h2,
.panel--dark h3,
.panel--dark h4 {
  color: var(--neon-green);
}

.panel--dark a {
  color: var(--neon-green);
}

.panel--dark a:hover {
  color: var(--paper);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
  margin: 32px 0;
}

.card {
  background: var(--paper);
  color: var(--ink);
  border: 2px solid var(--ink);
  border-radius: 2px 14px 2px 14px;
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: transform var(--tr), box-shadow var(--tr);
}

.card:hover {
  transform: translate(-3px, -3px) rotate(-0.6deg);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.35);
}

.card h3,
.card h4 {
  color: var(--ink);
  margin-bottom: 8px;
}

.card p {
  margin-bottom: 0;
  font-size: 14px;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--space-blue);
  opacity: 0.6;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 10px;
}

.grid {
  display: grid;
  gap: 24px;
}

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

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

.tag {
  display: inline-block;
  padding: 4px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--violet);
  border: 2px solid currentColor;
  border-radius: 20px;
  white-space: nowrap;
}

.tag--neon {
  color: var(--neon-green);
}

.tag--blue {
  color: var(--electric-blue);
}

.tag--red {
  color: var(--signal-red);
}

.visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 16 / 9;
  background-color: var(--graphite);
  background-image:
    linear-gradient(rgba(0, 255, 163, 0.1) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 255, 163, 0.1) 1px, transparent 1px);
  background-size: 24px 24px;
  border: 2px solid var(--space-blue);
  border-radius: var(--radius);
  overflow: hidden;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 14px;
}

.visual--skew {
  transform: rotate(-1.5deg);
}

.visual--skew:hover {
  transform: rotate(0deg);
  transition: transform var(--tr);
}

.visual--ratio-4-3 {
  aspect-ratio: 4 / 3;
}

.visual__content {
  position: relative;
  z-index: 1;
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 14px;
  text-align: center;
}

.visual__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  z-index: 1;
  padding: 4px 10px;
  background: rgba(11, 27, 61, 0.85);
  color: var(--neon-green);
  font-family: var(--font-mono);
  font-size: 12px;
  border-left: 3px solid var(--neon-green);
}

.toc {
  background: var(--graphite);
  border: 2px solid var(--space-blue);
  border-left: 4px solid var(--neon-green);
  padding: 24px;
  margin-bottom: 32px;
  border-radius: 2px 12px 2px 12px;
}

.toc__title {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--neon-green);
  margin-bottom: 12px;
  letter-spacing: 0.04em;
}

.toc__list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc__list a {
  color: var(--mist);
  font-size: 14px;
  display: block;
  padding: 4px 0;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.1);
  transition: color var(--tr), padding-left var(--tr);
}

.toc__list a:hover {
  color: var(--neon-green);
  padding-left: 6px;
}

.lede {
  font-size: 18px;
  line-height: 1.8;
  color: var(--mist);
  font-weight: 400;
}

.note {
  border-left: 3px solid var(--electric-blue);
  background: rgba(59, 130, 246, 0.08);
  padding: 16px 20px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  margin-bottom: 24px;
  border-radius: 0 8px 8px 0;
}

.index {
  counter-reset: index;
  margin: 24px 0;
}

.index li {
  counter-increment: index;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.index a {
  display: flex;
  gap: 12px;
  align-items: baseline;
  color: var(--mist);
  font-size: 15px;
  transition: color var(--tr);
}

.index a::before {
  content: counter(index, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--neon-green);
  flex-shrink: 0;
}

.index a:hover {
  color: var(--neon-green);
}

@media (max-width: 1024px) {
  .nav-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    right: 0;
    z-index: 150;
    width: min(320px, 84vw);
    height: calc(100vh - var(--header-h));
    background-color: var(--space-blue);
    background-image:
      linear-gradient(rgba(0, 255, 163, 0.05) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0, 255, 163, 0.05) 1px, transparent 1px);
    background-size: 24px 24px;
    border-left: 2px solid var(--neon-green);
    padding: 24px 20px;
    transform: translateX(100%);
    visibility: hidden;
    transition: transform var(--tr), visibility var(--tr);
    overflow-y: auto;
  }

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

  .nav__list {
    flex-direction: column;
    gap: 6px;
  }

  .nav__link {
    font-size: 16px;
    padding: 12px 14px;
    color: var(--paper);
  }

  .nav__link[aria-current="page"] {
    color: var(--space-blue);
  }

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

  .brand__sub {
    font-size: 11px;
  }
}

@media (max-width: 768px) {
  .site-header__inner {
    width: 94%;
    gap: 10px;
  }

  .brand__text {
    font-size: 16px;
  }

  .btn--v4 {
    padding: 8px 10px;
    font-size: 13px;
  }

  .btn--v4 .btn__dot {
    width: 6px;
    height: 6px;
  }

  .card {
    padding: 18px;
  }

  .page-head {
    padding: 24px 0 16px;
    margin-bottom: 24px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    margin-top: 32px;
    padding-top: 16px;
  }

  .site-footer__inner {
    padding-top: 40px;
  }
}

@media (max-width: 480px) {
  .brand__sub {
    display: none;
  }

  .site-header__actions {
    gap: 6px;
  }

  .nav-toggle {
    width: 40px;
    height: 40px;
  }
}

@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;
  }

  .btn:hover,
  .card:hover,
  .brand:hover .brand__mark,
  .visual--skew:hover {
    transform: none;
  }
}