:root {
  --color-bg: #101215;
  --color-panel: #171A1E;
  --color-panel-raised: #1F2329;
  --color-border: #2A3038;
  --color-border-soft: #232830;
  --color-tick: #3A424C;
  --color-accent: #E9F2FF;
  --color-accent-dark: #9DBDE6;
  --color-text: #F2F5F8;
  --color-text-muted: #98A2AE;
  --color-text-faint: #6C7683;
  --color-success: #6FD39A;
  --color-warn: #E8B26A;
  --color-error: #F06B6B;
  --color-cool: #7FB6F5;
  --color-shadow: rgba(0, 0, 0, .7);
  --color-shadow-soft: rgba(0, 0, 0, .4);
  --color-glow-strong: rgba(233, 242, 255, .55);
  --color-glow-medium: rgba(233, 242, 255, .28);
  --color-glow-soft: rgba(233, 242, 255, .12);
  --color-glow-faint: rgba(233, 242, 255, .05);
  --color-sweep: rgba(255, 255, 255, .55);
  --color-inset-light: rgba(255, 255, 255, .18);
  --color-inset-dark: rgba(0, 0, 0, .25);
  --color-flag-red: #D8323A;
  --color-flag-blue: #2E4E9E;
  --color-flag-hk: #D62B2B;
  --font-display: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'Noto Sans JP', 'Noto Sans KR', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, monospace;
  --radius-sm: 4px;
  --radius: 6px;
  --radius-round: 999px;
  --line-body: 1.65;
  --nav-height: 68px;
  --content-width: 1280px;
  --reading-width: 780px;
  --gutter: 40px;
  --section-space: 88px;
  --focus-size: 2px;
  --toc-offset: 126px;
  --transition-fast: 160ms ease;
  --transition-base: 260ms ease;
  --noise-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.92' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 16px);
  -webkit-text-size-adjust: 100%;
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  min-height: 100svh;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: var(--line-body);
  -webkit-font-smoothing: antialiased;
}

body::before {
  position: fixed;
  z-index: 80;
  inset: 0;
  background-image: var(--noise-image);
  background-size: 160px 160px;
  content: "";
  opacity: .05;
  pointer-events: none;
}

main,
section,
article,
aside,
header,
footer,
nav,
div {
  min-width: 0;
}

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

img {
  height: auto;
}

button,
input,
select,
textarea {
  color: inherit;
  font: inherit;
}

button,
summary {
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

p,
h1,
h2,
h3,
h4,
ul,
ol,
blockquote,
figure {
  margin: 0;
}

ul,
ol {
  padding: 0;
}

ul {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  color: var(--color-text);
  text-wrap: balance;
}

h1 {
  font-size: clamp(52px, 5.2vw, 72px);
  font-weight: 900;
  letter-spacing: -.015em;
  line-height: 1.1;
}

h2 {
  font-size: clamp(34px, 3.8vw, 52px);
  font-weight: 900;
  letter-spacing: -.012em;
  line-height: 1.14;
}

h3 {
  font-size: clamp(21px, 2vw, 28px);
  font-weight: 800;
  line-height: 1.25;
}

p {
  color: var(--color-text-muted);
}

strong {
  color: var(--color-text);
  font-weight: 650;
}

small {
  color: var(--color-text-muted);
}

code,
kbd,
pre,
samp {
  font-family: var(--font-mono);
}

code {
  overflow-wrap: anywhere;
}

pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 18px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel-raised);
  color: var(--color-accent);
  -webkit-overflow-scrolling: touch;
}

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

:where(a, button, input, select, textarea, summary, [role="tab"]):focus-visible {
  outline: var(--focus-size) solid var(--color-accent);
  outline-offset: 3px;
}

.wrap {
  width: 100%;
  max-width: var(--content-width);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.reading-wrap {
  width: 100%;
  max-width: calc(var(--reading-width) + (var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-top: var(--section-space);
  padding-bottom: var(--section-space);
  overflow-x: clip;
}

.section-head {
  display: grid;
  max-width: 820px;
  gap: 14px;
  margin-bottom: 36px;
}

.section-kicker,
.eyebrow {
  font-family: var(--font-mono);
  color: var(--color-accent-dark);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.no-break {
  white-space: nowrap;
}

.muted {
  color: var(--color-text-muted);
}

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

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

.btn {
  display: inline-flex;
  min-width: 24px;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 22px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: transparent;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 750;
  line-height: 1;
  text-align: center;
  white-space: nowrap;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}

.btn:hover {
  border-color: var(--color-accent-dark);
}

.btn:active {
  transform: translateY(1px);
}

.btn.btn-primary {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-bg);
  box-shadow: 0 0 0 1px var(--color-glow-soft), 0 0 18px var(--color-glow-medium), 0 0 44px var(--color-glow-faint);
}

.btn-primary:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-glow-medium), 0 0 26px var(--color-glow-strong), 0 0 60px var(--color-glow-soft);
}

.btn-secondary {
  background: var(--color-panel-raised);
}

.btn-small {
  min-height: 36px;
  padding-inline: 14px;
  font-size: 13px;
}

.badge,
.tag {
  display: inline-flex;
  max-width: 100%;
  min-height: 26px;
  align-items: center;
  gap: 8px;
  overflow: hidden;
  padding: 3px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .02em;
  white-space: nowrap;
}

.badge-dot,
.status-dot {
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  border-radius: var(--radius-round);
  background: var(--color-accent);
  box-shadow: 0 0 8px var(--color-glow-strong);
}

.tag-success {
  border-color: var(--color-success);
  color: var(--color-success);
}

.tag-warn {
  border-color: var(--color-warn);
  color: var(--color-warn);
}

.panel,
.card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel);
}

.card {
  padding: 24px;
  box-shadow: 0 22px 48px -36px var(--color-shadow);
}

.card:hover {
  border-color: var(--color-tick);
}

.window-chrome {
  display: flex;
  min-height: 36px;
  align-items: center;
  gap: 12px;
  padding-inline: 14px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel-raised);
}

.window-dots {
  display: flex;
  gap: 6px;
}

.window-dots i {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-round);
  background: var(--color-tick);
}

.window-title {
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
}

.reveal {
  transition: opacity .55s ease, transform .55s ease;
}

.reveal.pending {
  opacity: 0;
  transform: translateY(16px);
}

.reveal.shown {
  opacity: 1;
  transform: translateY(0);
}

.site-header {
  position: relative;
  z-index: 60;
  height: var(--nav-height);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

.site-header-inner {
  display: flex;
  height: 100%;
  align-items: center;
  gap: 32px;
}

.site-brand {
  display: inline-flex;
  min-height: 44px;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
}

.site-brand img {
  width: 26px;
  height: 26px;
}

.site-brand-name {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 900;
  letter-spacing: .01em;
}

.site-brand-local {
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 500;
}

.desktop-nav {
  display: flex;
  height: 100%;
  flex: 1 1 auto;
  align-items: center;
  gap: 2px;
}

.desktop-nav a {
  position: relative;
  display: inline-flex;
  height: var(--nav-height);
  align-items: center;
  justify-content: center;
  padding-inline: 10px;
  color: var(--color-text-muted);
  font-size: 13.5px;
  font-weight: 500;
  white-space: nowrap;
}

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

.desktop-nav a[aria-current="page"] {
  font-weight: 650;
}

.desktop-nav a[aria-current="page"]::after {
  position: absolute;
  right: 10px;
  bottom: -1px;
  left: 10px;
  height: 2px;
  border-radius: var(--radius-round);
  background: var(--color-accent);
  box-shadow: 0 0 10px var(--color-glow-medium);
  content: "";
}

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
}

.language-control {
  position: relative;
}

.language-button {
  display: inline-flex;
  min-width: 24px;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding-inline: 10px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: transparent;
  color: var(--color-text-muted);
  font-size: 13px;
}

.language-button:hover,
.language-button[aria-expanded="true"] {
  border-color: var(--color-border);
  color: var(--color-text);
}

.language-menu {
  position: absolute;
  z-index: 75;
  top: calc(100% + 8px);
  right: 0;
  display: none;
  width: 164px;
  padding: 6px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel-raised);
  box-shadow: 0 18px 42px var(--color-shadow);
}

.language-menu.is-open {
  display: grid;
}

.language-menu a {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding-inline: 10px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 13px;
}

.language-menu a:hover,
.language-menu a[aria-current="true"] {
  background: var(--color-panel);
  color: var(--color-text);
}

.header-login {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  padding-inline: 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel-raised);
  color: var(--color-text);
  font-size: 13px;
  font-weight: 650;
}

.header-login:hover {
  border-color: var(--color-accent-dark);
  box-shadow: 0 0 0 1px var(--color-glow-soft);
}

.menu-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel);
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  width: 18px;
  height: 1px;
  background: var(--color-text);
}

.menu-toggle-lines {
  position: relative;
}

.menu-toggle-lines::before,
.menu-toggle-lines::after {
  position: absolute;
  left: 0;
  content: "";
}

.menu-toggle-lines::before {
  top: -6px;
}

.menu-toggle-lines::after {
  top: 6px;
}

.mobile-nav {
  position: absolute;
  z-index: 72;
  top: var(--nav-height);
  right: 0;
  left: 0;
  display: none;
  max-height: calc(100dvh - var(--nav-height));
  overflow-y: auto;
  padding: 12px var(--gutter) 20px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel);
  overscroll-behavior: contain;
}

.mobile-nav.is-open {
  display: block;
}

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  border-bottom: 1px solid var(--color-border-soft);
  color: var(--color-text-muted);
}

.mobile-nav a[aria-current="page"] {
  color: var(--color-accent);
  font-weight: 700;
}

.mobile-language-links {
  display: grid;
  margin-top: 12px;
}

.nav-veil {
  position: fixed;
  z-index: 55;
  inset: var(--nav-height) 0 0;
  display: none;
  background: var(--color-shadow-soft);
}

.nav-veil.is-open {
  display: block;
}

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr 1fr;
  gap: 56px;
  padding-top: 56px;
  padding-bottom: 38px;
}

.footer-brand {
  display: grid;
  align-content: start;
  gap: 16px;
}

.footer-brand .site-brand {
  justify-self: start;
}

.footer-brand p {
  max-width: 440px;
  font-size: 14px;
}

.footer-heading {
  margin-bottom: 14px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 18px;
}

.footer-links a,
.footer-keywords a,
.footer-languages a,
.footer-legal a {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 13px;
}

.footer-links a:hover,
.footer-keywords a:hover,
.footer-languages a:hover,
.footer-legal a:hover {
  color: var(--color-accent);
}

.footer-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-keywords a {
  min-height: 32px;
  padding-inline: 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-panel-raised);
}

.footer-bottom {
  display: flex;
  min-height: 64px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-faint);
  font-family: var(--font-mono);
  font-size: 11.5px;
}

.footer-languages,
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.prose {
  color: var(--color-text-muted);
}

.prose > * + * {
  margin-top: 18px;
}

.prose h2 {
  margin-top: 58px;
}

.prose h3 {
  margin-top: 36px;
}

.prose ul,
.prose ol {
  padding-left: 22px;
}

.prose ul {
  list-style: square;
}

.prose ol {
  list-style: decimal;
}

.prose a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-dark);
  text-underline-offset: 3px;
}

.prose table {
  border-collapse: collapse;
}

.prose th,
.prose td {
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  text-align: left;
}

.prose th {
  background: var(--color-panel-raised);
  color: var(--color-text);
}

[data-counter] {
  display: inline-block;
  min-width: 3ch;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: var(--toc-offset);
}

@media (max-width: 1120px) {
  .desktop-nav {
    display: none;
  }

  .header-tools {
    margin-left: auto;
  }

  .menu-toggle {
    display: inline-flex;
  }
}

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --section-space: 64px;
  }

  h1 {
    font-size: clamp(28px, 9.5vw, 40px);
    letter-spacing: -.01em;
  }

  h2 {
    font-size: clamp(28px, 8vw, 38px);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    padding-top: 18px;
    padding-bottom: 18px;
  }
}

@media (max-width: 640px) {
  :root {
    --gutter: 16px;
  }

  .site-header-inner {
    gap: 8px;
  }

  .site-brand-name {
    font-size: 16px;
  }

  .language-control {
    display: none;
  }

  .header-login {
    padding-inline: 11px;
  }

  .mobile-nav {
    padding-inline: var(--gutter);
  }

  .btn {
    max-width: 100%;
  }

  .footer-links {
    grid-template-columns: 1fr 1fr;
  }

  .tilt,
  [class*="tilt-"] {
    transform: none;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: .01ms !important;
  }

  .reveal,
  .reveal.pending {
    opacity: 1;
    transform: none;
  }
}