:root {
  --color-bg: #191614;
  --color-panel: #201C19;
  --color-panel-raised: #292420;
  --color-border: #3A322B;
  --color-accent: #FF9C7E;
  --color-accent-dark: #E0745A;
  --color-text: #F3EDE7;
  --color-text-muted: #A89C90;
  --color-success: #7DC98F;
  --color-warning: #E8B25C;
  --color-error: #E06555;
  --color-shadow: rgba(9, 6, 4, 0.62);
  --color-shadow-accent: rgba(224, 116, 90, 0.1);
  --color-button-glow: rgba(224, 116, 90, 0.35);
  --color-glow-soft: rgba(255, 156, 126, 0.1);
  --color-glow-ring: rgba(255, 156, 126, 0.22);
  --color-glow-halo: rgba(255, 156, 126, 0.07);
  --color-accent-faint: rgba(255, 156, 126, 0.06);
  --color-focus-shadow: rgba(255, 156, 126, 0.26);
  --color-overlay: rgba(25, 22, 20, 0.82);
  --color-noise: rgba(243, 237, 231, 0.05);
  --color-flag-red: #C6493C;
  --color-flag-blue: #44598F;
  --color-flag-white: #EDE6DE;
  --color-flag-green: #3F7853;
  --font-display: Georgia, "Times New Roman", "Songti SC", "Noto Serif CJK SC", serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Consolas, "Courier New", monospace;
  --radius-large: 24px;
  --radius-medium: 14px;
  --radius-small: 9px;
  --radius-pill: 999px;
  --shadow-card: 0 34px 70px -26px var(--color-shadow), 0 12px 32px -10px var(--color-shadow-accent);
  --shadow-panel: 0 24px 54px -34px var(--color-shadow);
  --page-max: 1320px;
  --content-max: 1080px;
  --reading-max: 760px;
  --gutter: clamp(16px, 4vw, 44px);
  --header-height: 76px;
  --section-space: clamp(76px, 11vw, 144px);
  --toc-offset: 92px;
  --transition-fast: 180ms ease;
  --transition-medium: 420ms cubic-bezier(0.2, 0.75, 0.25, 1);
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  background: var(--color-bg);
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  position: fixed;
  z-index: 90;
  inset: 0;
  pointer-events: none;
  content: "";
  opacity: 0.05;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='140' height='140'><filter id='g'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/></filter><rect width='140' height='140' filter='url(%23g)'/></svg>");
}

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

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

img {
  height: auto;
}

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

button {
  cursor: pointer;
}

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

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

ul,
ol {
  padding: 0;
}

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

h1,
h2,
h3 {
  color: var(--color-text);
  font-family: var(--font-display);
  font-weight: 400;
  text-wrap: balance;
}

h1,
.hero-title {
  font-size: clamp(52px, 6vw, 72px);
  line-height: 1.12;
  letter-spacing: 0;
}

h2,
.section-title {
  font-size: clamp(36px, 4.2vw, 56px);
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  font-size: clamp(24px, 2.5vw, 34px);
  line-height: 1.25;
}

p + p {
  margin-top: 1em;
}

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

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

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

:not(pre) > code {
  padding: 0.15em 0.42em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  background: var(--color-panel-raised);
  color: var(--color-text);
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel);
  color: var(--color-text);
  -webkit-overflow-scrolling: touch;
}

pre code {
  white-space: pre;
}

:where(a, button, input, select, textarea, summary, [role="tab"], [tabindex]):focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  box-shadow: 0 0 0 5px var(--color-focus-shadow);
}

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

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

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

.text-accent,
.title-accent {
  color: var(--color-accent);
}

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

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

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

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

.section-compact {
  padding-top: clamp(52px, 7vw, 88px);
  padding-bottom: clamp(52px, 7vw, 88px);
}

.section-head {
  display: grid;
  gap: 18px;
  max-width: 800px;
  margin-bottom: clamp(42px, 6vw, 76px);
}

.eyebrow {
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.lead {
  max-width: 720px;
  color: var(--color-text-muted);
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.65;
}

.panel,
.card {
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-large);
  background: var(--color-panel);
  box-shadow: var(--shadow-panel);
}

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

.card-pad {
  padding: clamp(22px, 3vw, 34px);
}

.badge,
.fact-pill,
.tag {
  display: inline-flex;
  min-height: 28px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.4;
  text-overflow: ellipsis;
}

.badge-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  box-shadow: 0 0 10px var(--color-glow-ring);
}

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

.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.btn {
  display: inline-flex;
  min-width: 24px;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 30px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-weight: 650;
  line-height: 1.2;
  text-align: center;
  transition: transform var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast), color var(--transition-fast);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(180deg, var(--color-accent), var(--color-accent-dark));
  color: var(--color-bg);
  box-shadow: 0 10px 28px -8px var(--color-button-glow);
}

.btn-primary:hover {
  box-shadow: 0 14px 34px -8px var(--color-button-glow);
}

.btn-secondary {
  border-color: var(--color-border);
  background: transparent;
  color: var(--color-text);
}

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

.btn-small {
  min-height: 40px;
  padding: 9px 20px;
  font-size: 14px;
}

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
  box-shadow: none;
}

.reveal {
  transition: opacity 620ms ease, transform 620ms cubic-bezier(0.2, 0.75, 0.25, 1);
}

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

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

#site-header {
  position: relative;
  z-index: 80;
  min-height: var(--header-height);
}

.site-head {
  position: relative;
  z-index: 80;
  width: 100%;
  border-bottom: 1px solid transparent;
  background: var(--color-bg);
}

.site-head-inner {
  display: flex;
  width: 100%;
  max-width: var(--page-max);
  min-height: var(--header-height);
  align-items: center;
  gap: 28px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

.site-brand img {
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
}

.brand-copy {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
}

.brand-name {
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 650;
  letter-spacing: 0.04em;
}

.brand-local {
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 450;
}

.desktop-nav {
  display: flex;
  flex: 1 1 auto;
  justify-content: center;
}

.desktop-nav ul {
  display: flex;
  align-items: center;
  list-style: none;
}

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

.desktop-nav li + li::before {
  margin-inline: 13px;
  color: var(--color-text-muted);
  content: "·";
  font-size: 13px;
  opacity: 0.5;
}

.desktop-nav a {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 14px;
  transition: color var(--transition-fast);
}

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

.header-tools {
  position: relative;
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
}

.language-control {
  position: relative;
}

.language-button {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 10px;
  border: 0;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 13px;
}

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

.language-menu {
  position: absolute;
  z-index: 85;
  top: calc(100% + 8px);
  right: 0;
  width: 176px;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-card);
}

.language-menu[hidden] {
  display: none;
}

.language-menu a {
  display: flex;
  min-height: 42px;
  align-items: center;
  justify-content: space-between;
  padding: 8px 11px;
  border-radius: var(--radius-small);
  color: var(--color-text-muted);
  font-size: 14px;
}

.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: 40px;
  align-items: center;
  justify-content: center;
  padding: 8px 20px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text);
  font-size: 13px;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.header-login:hover {
  border-color: var(--color-accent-dark);
  background: var(--color-panel-raised);
}

.menu-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  height: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  display: block;
  width: 18px;
  height: 1px;
  background: var(--color-text);
  content: "";
  transition: transform var(--transition-fast);
}

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

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

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

.menu-toggle[aria-expanded="true"] .menu-toggle-lines {
  background: transparent;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::before {
  top: 0;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::after {
  top: 0;
  transform: rotate(-45deg);
}

.mobile-drawer {
  display: none;
}

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

.footer-main {
  display: grid;
  grid-template-columns: minmax(240px, 1.25fr) repeat(2, minmax(180px, 1fr));
  gap: clamp(34px, 6vw, 84px);
  padding-top: 72px;
  padding-bottom: 56px;
}

.footer-brand {
  display: grid;
  align-content: start;
  gap: 16px;
  max-width: 420px;
}

.footer-brand-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 11px;
}

.footer-brand-link img {
  width: 28px;
  height: 28px;
}

.footer-brand p {
  color: var(--color-text-muted);
  font-size: 14px;
}

.footer-group {
  display: grid;
  align-content: start;
  gap: 14px;
}

.footer-title {
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.footer-links {
  display: grid;
  gap: 4px;
  list-style: none;
}

.footer-links a {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 14px;
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-keywords,
.footer-languages {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
}

.footer-keywords a,
.footer-languages a {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 13px;
}

.footer-keywords a:hover,
.footer-languages a:hover,
.footer-languages a[aria-current="true"] {
  color: var(--color-accent);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 22px;
  padding-bottom: 28px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
}

.footer-legal a {
  min-height: 28px;
}

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

.prose > * + * {
  margin-top: 1.25em;
}

.prose h2 {
  margin-top: 2.2em;
  color: var(--color-text);
}

.prose h3 {
  margin-top: 1.8em;
  color: var(--color-text);
}

.prose ul,
.prose ol {
  padding-left: 1.4em;
}

.prose li + li {
  margin-top: 0.5em;
}

.prose a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-dark);
  text-underline-offset: 0.2em;
}

.prose img {
  border-radius: var(--radius-medium);
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: calc(var(--toc-offset) + 28px);
}

@media (max-width: 1180px) {
  .desktop-nav li + li::before {
    margin-inline: 8px;
  }

  .desktop-nav a {
    font-size: 13px;
  }

  .site-head-inner {
    gap: 18px;
  }
}

@media (max-width: 980px) {
  .desktop-nav,
  .language-control {
    display: none;
  }

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

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

  .mobile-drawer {
    position: absolute;
    z-index: 82;
    top: 100%;
    left: 0;
    display: none;
    width: 100%;
    max-height: calc(100dvh - var(--header-height));
    overflow-y: auto;
    overscroll-behavior: contain;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    background: var(--color-panel-raised);
    box-shadow: var(--shadow-card);
  }

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

  .mobile-drawer-inner {
    width: 100%;
    max-width: var(--page-max);
    margin-inline: auto;
    padding: 10px var(--gutter) 22px;
  }

  .mobile-drawer ul {
    list-style: none;
  }

  .mobile-drawer a {
    display: flex;
    width: 100%;
    min-height: 48px;
    align-items: center;
    justify-content: space-between;
    padding: 10px 4px;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text-muted);
  }

  .mobile-drawer a:hover,
  .mobile-drawer a.is-active,
  .mobile-drawer a[aria-current="page"],
  .mobile-drawer a[aria-current="true"] {
    color: var(--color-text);
  }

  .mobile-language-list {
    margin-top: 14px;
  }

  .mobile-language-label {
    padding: 8px 4px;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.12em;
  }

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

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  h1,
  .hero-title {
    font-size: clamp(32px, 9.5vw, 40px);
    line-height: 1.15;
  }

  h2,
  .section-title {
    font-size: clamp(30px, 8vw, 40px);
  }

  .section {
    padding-top: 74px;
    padding-bottom: 74px;
  }

  .decorative-tilt,
  [data-decorative-tilt] {
    transform: none;
  }

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

  .footer-brand {
    grid-column: auto;
  }
}

@media (max-width: 640px) {
  :root {
    --header-height: 68px;
    --gutter: 18px;
    --toc-offset: 82px;
  }

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

  .site-head-inner {
    gap: 10px;
  }

  .brand-local {
    display: none;
  }

  .brand-name {
    font-size: 15px;
  }

  .header-login {
    min-width: 58px;
    padding-inline: 14px;
  }

  .button-row {
    width: 100%;
  }

  .button-row .btn {
    flex: 1 1 140px;
  }

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 374px) {
  .site-brand {
    gap: 7px;
  }

  .site-brand img {
    width: 21px;
    height: 21px;
  }

  .header-tools {
    gap: 6px;
  }

  .header-login {
    min-width: 52px;
    padding-inline: 11px;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto;
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
  }

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