:root {
  --color-bg: #F3EBDB;
  --color-bg-top: #F8F2E6;
  --color-panel: #FBF7EE;
  --color-panel-alt: #EAE0CB;
  --color-border: #D8CBB3;
  --color-accent: #2C6B6F;
  --color-accent-dark: #1F5054;
  --color-text: #2A211A;
  --color-text-muted: #6E6255;
  --color-success: #3F7D4E;
  --color-warn: #B9791F;
  --color-error: #B2402E;
  --color-rail-top-a: #EDE0C8;
  --color-rail-top-b: #D6C4A2;
  --color-rail-side-a: #3A2E25;
  --color-rail-side-b: #2A211A;
  --color-rail-graphite: #463A30;
  --color-contact: #1A120C;
  --color-flag-red: #C8332B;
  --color-flag-blue: #2F4C8E;
  --color-flag-white: #FBF7EE;
  --color-transparent: transparent;
  --color-paper-wash: rgba(251, 247, 238, .75);
  --color-paper-glass: rgba(251, 247, 238, .92);
  --color-border-soft: rgba(216, 203, 179, .7);
  --color-accent-05: rgba(44, 107, 111, .05);
  --color-accent-08: rgba(44, 107, 111, .08);
  --color-accent-10: rgba(44, 107, 111, .10);
  --color-accent-14: rgba(44, 107, 111, .14);
  --color-accent-18: rgba(44, 107, 111, .18);
  --color-accent-35: rgba(44, 107, 111, .35);
  --color-accent-55: rgba(44, 107, 111, .55);
  --color-accent-65: rgba(44, 107, 111, .65);
  --color-text-05: rgba(42, 33, 26, .05);
  --color-text-06: rgba(42, 33, 26, .06);
  --color-text-08: rgba(42, 33, 26, .08);
  --color-text-12: rgba(42, 33, 26, .12);
  --color-text-18: rgba(42, 33, 26, .18);
  --color-white-18: rgba(255, 255, 255, .18);
  --color-white-22: rgba(255, 255, 255, .22);
  --color-white-42: rgba(255, 255, 255, .42);
  --color-white-65: rgba(255, 255, 255, .65);
  --font-display: Georgia, "Iowan Old Style", "Palatino Linotype", "Songti SC", "STSong", "Source Han Serif SC", "Noto Serif CJK SC", serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;
  --radius-small: 6px;
  --radius-medium: 8px;
  --header-height: 72px;
  --content-width: 1280px;
  --reading-width: 760px;
  --gutter: 32px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 40px;
  --space-6: 48px;
  --space-8: 64px;
  --space-10: 80px;
  --shadow-panel: 0 18px 40px -18px var(--color-accent-14), 0 2px 6px var(--color-text-05);
  --shadow-raised: 0 24px 56px -24px var(--color-accent-18), 0 3px 8px var(--color-text-06);
  --shadow-button: 0 10px 24px -10px var(--color-accent-55), inset 0 1px 0 var(--color-white-18);
  --shadow-inner: inset 0 1px 0 var(--color-white-65);
  --focus-ring: 2px solid var(--color-accent);
  --transition-fast: 180ms ease;
  --transition-reveal: 620ms cubic-bezier(.22, .75, .25, 1);
  --toc-offset: 136px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + var(--space-2));
  -webkit-text-size-adjust: 100%;
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 0;
  min-height: 100svh;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  pointer-events: none;
  content: "";
  opacity: .04;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='g'><feTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/></filter><rect width='180' height='180' filter='url(%23g)'/></svg>");
  background-size: 180px 180px;
}

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

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

svg {
  display: block;
  flex-shrink: 0;
}

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

button {
  cursor: pointer;
}

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

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

p:last-child,
ul:last-child,
ol:last-child,
blockquote:last-child {
  margin-bottom: 0;
}

ul,
ol {
  padding-left: 1.35em;
}

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

h1 {
  margin-bottom: var(--space-3);
  font-family: var(--font-display);
  font-size: clamp(52px, 5.15vw, 68px);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -.02em;
}

h2 {
  margin-bottom: var(--space-2);
  font-family: var(--font-display);
  font-size: clamp(34px, 4vw, 48px);
  font-weight: 400;
  line-height: 1.18;
  letter-spacing: -.015em;
}

h3 {
  margin-bottom: var(--space-1);
  font-size: clamp(21px, 2vw, 26px);
  font-weight: 600;
  line-height: 1.3;
}

h4 {
  margin-bottom: var(--space-1);
  font-size: 18px;
  line-height: 1.4;
}

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

:not(pre) > code {
  padding: .12em .35em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  background: var(--color-panel-alt);
  font-size: .9em;
}

pre {
  max-width: 100%;
  padding: var(--space-3);
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-text);
  color: var(--color-panel);
  line-height: 1.7;
  -webkit-overflow-scrolling: touch;
}

pre code {
  white-space: pre;
}

hr {
  height: 1px;
  margin: var(--space-6) 0;
  border: 0;
  background: var(--color-border);
}

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

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

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

.section {
  padding-top: var(--space-10);
  padding-bottom: var(--space-10);
}

.section-compact {
  padding-top: var(--space-6);
  padding-bottom: var(--space-6);
}

.section-head {
  max-width: 760px;
  margin-bottom: var(--space-6);
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  min-height: 28px;
  margin-bottom: var(--space-2);
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.section-kicker::before {
  width: 20px;
  height: 2px;
  flex-shrink: 0;
  background: var(--color-accent);
  content: "";
}

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

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

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

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

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

.panel {
  padding: clamp(24px, 4vw, 48px);
}

.card {
  padding: var(--space-3);
}

.badge,
.tag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 28px;
  max-width: 100%;
  padding: 3px 10px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  background: var(--color-panel);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.3;
  text-overflow: ellipsis;
}

.badge-accent {
  border-color: var(--color-accent);
  background: var(--color-accent-08);
  color: var(--color-accent-dark);
}

.status-dot {
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-14);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-width: 24px;
  min-height: 48px;
  padding: 10px 24px;
  border: 1px solid var(--color-transparent);
  border-radius: var(--radius-medium);
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  text-align: center;
  transition: transform var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast), box-shadow var(--transition-fast);
}

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

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

.btn-primary {
  border-color: var(--color-accent-dark);
  background: linear-gradient(180deg, var(--color-accent), var(--color-accent-dark));
  color: var(--color-panel);
  box-shadow: var(--shadow-button);
}

.btn-primary:hover {
  box-shadow: 0 14px 28px -10px var(--color-accent-65), inset 0 1px 0 var(--color-white-22);
}

.btn-secondary,
.btn-ghost {
  border-color: var(--color-border);
  background: var(--color-panel);
  color: var(--color-text);
  box-shadow: var(--shadow-inner), 0 1px 2px var(--color-text-05);
}

.btn-secondary:hover,
.btn-ghost:hover {
  border-color: var(--color-accent);
}

.btn-small {
  min-height: 38px;
  padding: 8px 16px;
  font-size: 14px;
}

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: .55;
  transform: none;
}

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

.reveal {
  transition: opacity var(--transition-reveal), transform var(--transition-reveal);
}

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

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

.site-header {
  position: relative;
  z-index: 50;
  min-height: var(--header-height);
  border-bottom: 1px solid var(--color-border-soft);
  background: linear-gradient(180deg, var(--color-paper-glass), var(--color-paper-wash));
}

.header-shell {
  position: relative;
  display: flex;
  align-items: center;
  min-height: var(--header-height);
  gap: var(--space-3);
}

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

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

.brand-word {
  font-family: var(--font-display);
  font-size: 22px;
  line-height: 1;
  letter-spacing: .02em;
}

.brand-local {
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 400;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
}

.desktop-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 40px;
  padding: 7px 9px;
  border-radius: var(--radius-small);
  color: var(--color-text-muted);
  font-size: 13px;
  transition: color var(--transition-fast), background var(--transition-fast);
}

.desktop-nav a svg {
  width: 16px;
  height: 16px;
}

.desktop-nav a:hover,
.desktop-nav a.is-active {
  background: var(--color-paper-wash);
  color: var(--color-text);
}

.desktop-nav a:hover svg,
.desktop-nav a.is-active svg {
  color: var(--color-accent);
}

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

.language-picker {
  position: relative;
}

.language-toggle,
.menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  border: 0;
  border-radius: var(--radius-small);
  background: var(--color-transparent);
  color: var(--color-text-muted);
}

.language-toggle {
  gap: 5px;
  padding-inline: 8px;
  font-size: 13px;
}

.language-menu {
  position: absolute;
  z-index: 70;
  top: calc(100% + 8px);
  right: 0;
  width: 164px;
  padding: 6px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel);
  box-shadow: var(--shadow-raised);
}

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

.language-menu a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 10px;
  border-radius: var(--radius-small);
  color: var(--color-text-muted);
  font-size: 13px;
}

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

.header-login {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 8px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-small);
  background: var(--color-panel);
  box-shadow: var(--shadow-inner), 0 1px 2px var(--color-text-06);
  font-size: 14px;
  font-weight: 600;
}

.menu-toggle {
  display: none;
}

.menu-toggle svg {
  width: 22px;
  height: 22px;
}

.mobile-nav {
  display: none;
}

.mobile-nav a {
  width: 100%;
}

.mobile-nav-veil {
  display: none;
}

.site-footer {
  position: relative;
  overflow-x: clip;
  border-top: 1px solid var(--color-border);
  background: linear-gradient(180deg, var(--color-panel-alt), var(--color-bg));
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1.2fr .8fr;
  gap: var(--space-6);
  padding-top: var(--space-8);
  padding-bottom: var(--space-6);
}

.footer-brand {
  max-width: 320px;
}

.footer-brand .site-brand {
  margin-bottom: var(--space-2);
}

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

.footer-column h2 {
  margin-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.footer-links {
  display: grid;
  gap: 7px;
  padding: 0;
  list-style: none;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding-top: var(--space-3);
  padding-bottom: var(--space-3);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 13px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

#server-status {
  position: static;
  display: block;
  max-width: 100%;
  margin-top: var(--space-4);
  margin-bottom: var(--space-4);
  overflow: hidden;
}

#server-status + * {
  margin-top: var(--space-4);
}

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

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

.prose h2,
.prose h3,
.prose h4,
.prose strong {
  color: var(--color-text);
}

.prose h2 {
  margin-top: 2em;
}

.prose h3 {
  margin-top: 1.6em;
}

.prose a:not(.btn) {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-35);
  text-underline-offset: .18em;
}

.prose li + li {
  margin-top: .5em;
}

.tilt,
.tilt-card {
  transform: rotate(-.25deg);
}

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

@media (max-width: 1120px) {
  .desktop-nav a {
    padding-inline: 7px;
    font-size: 12px;
  }

  .desktop-nav a svg {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
  }

  .footer-grid > :last-child {
    grid-column: 2 / -1;
  }
}

@media (max-width: 900px) {
  .desktop-nav,
  .language-picker {
    display: none;
  }

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

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

  .mobile-nav-veil {
    position: fixed;
    z-index: 48;
    inset: var(--header-height) 0 0;
    background: var(--color-text-18);
  }

  html.nav-open .mobile-nav-veil {
    display: block;
  }

  .mobile-nav {
    position: absolute;
    z-index: 60;
    top: 100%;
    right: var(--gutter);
    left: var(--gutter);
    max-height: calc(100dvh - var(--header-height) - 16px);
    padding: 8px;
    overflow-y: auto;
    overscroll-behavior: contain;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-medium);
    background: var(--color-panel);
    box-shadow: var(--shadow-raised);
  }

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

  .mobile-nav ul {
    display: grid;
    gap: 3px;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .mobile-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    min-height: 46px;
    padding: 10px 12px;
    border-radius: var(--radius-small);
    color: var(--color-text-muted);
  }

  .mobile-nav a:hover,
  .mobile-nav a.is-active {
    background: var(--color-panel-alt);
    color: var(--color-text);
  }

  .mobile-nav a svg {
    width: 18px;
    height: 18px;
    color: var(--color-accent);
  }

  .mobile-language {
    margin-top: 6px;
    padding-top: 6px;
    border-top: 1px solid var(--color-border);
  }

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

  .footer-grid > :last-child {
    grid-column: auto;
  }
}

@media (max-width: 768px) {
  h1 {
    font-size: clamp(34px, 9.5vw, 40px);
  }

  h2 {
    font-size: clamp(29px, 8vw, 38px);
  }

  .section {
    padding-top: var(--space-8);
    padding-bottom: var(--space-8);
  }

  .section-head {
    margin-bottom: var(--space-4);
  }

  .footer-grid {
    gap: var(--space-4);
  }
}

@media (max-width: 640px) {
  :root {
    --gutter: 20px;
  }

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

  .wrap,
  .reading {
    padding-inline: var(--gutter);
  }

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

  .header-shell {
    gap: 8px;
  }

  .brand-local {
    display: none;
  }

  .header-login {
    min-height: 38px;
    padding-inline: 13px;
  }

  .mobile-nav {
    right: var(--gutter);
    left: var(--gutter);
    max-width: calc(100% - (var(--gutter) * 2));
  }

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

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

  .panel,
  .card {
    max-width: 100%;
  }

  .btn {
    max-width: 100%;
  }

  .decorative,
  .stripe-halo,
  [class*="watermark"] {
    max-width: 100%;
    transform: none;
  }
}

@media (max-width: 360px) {
  :root {
    --gutter: 16px;
  }

  .brand-word {
    font-size: 20px;
  }

  .header-login {
    padding-inline: 10px;
  }
}

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

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

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