:root {
  --color-bg: #E7EEF6;
  --color-panel: #F6F9FD;
  --color-panel-strong: #DCE6F1;
  --color-surface: #FFFFFF;
  --color-border: #C7D4E3;
  --color-accent: #C9553B;
  --color-accent-dark: #A9412B;
  --color-apricot: #E8935A;
  --color-text: #1B2434;
  --color-muted: #5B6B80;
  --color-mist: #7E93AC;
  --color-success: #2E8B62;
  --color-warning: #C98A1E;
  --color-error: #A61E38;
  --color-on-accent: #FFFFFF;
  --color-footer: #1B2434;
  --color-footer-muted: #C7D4E3;
  --color-overlay: rgba(27, 36, 52, 0.42);
  --color-glow: rgba(232, 147, 90, 0.07);
  --color-glow-strong: rgba(232, 147, 90, 0.11);
  --color-shadow-accent: rgba(201, 85, 59, 0.10);
  --color-shadow-accent-strong: rgba(201, 85, 59, 0.30);
  --color-shadow-cool: rgba(27, 36, 52, 0.08);
  --color-highlight: rgba(255, 255, 255, 0.74);
  --color-highlight-soft: rgba(255, 255, 255, 0.50);
  --color-edge: rgba(27, 36, 52, 0.12);
  --color-accent-tint: rgba(201, 85, 59, 0.08);
  --color-success-tint: rgba(46, 139, 98, 0.10);
  --color-mist-tint: rgba(126, 147, 172, 0.14);
  --color-white-inset: rgba(255, 255, 255, 0.35);
  --color-switch-shadow: rgba(27, 36, 52, 0.20);
  --color-flag-red: #D7263D;
  --color-flag-blue: #1F4E9B;
  --color-flag-navy: #26437A;
  --color-flag-white: #FFFFFF;
  --font-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, 'Liberation Mono', monospace;
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-pill: 999px;
  --page-width: 1320px;
  --content-width: 960px;
  --header-height: 72px;
  --gutter: 40px;
  --section-space: 104px;
  --focus-size: 2px;
  --shadow-panel: 0 40px 80px -28px var(--color-shadow-accent), 0 24px 48px -20px var(--color-shadow-cool);
  --shadow-card: 0 18px 42px -24px var(--color-shadow-accent), 0 8px 20px -16px var(--color-shadow-cool);
  --shadow-button: 0 12px 26px -10px var(--color-shadow-accent-strong);
  --toc-offset: 116px;
}

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

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

html.nav-open {
  overflow: hidden;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: clip;
  color: var(--color-text);
  background:
    radial-gradient(68% 46% at 52% 0%, var(--color-glow-strong), transparent 72%),
    linear-gradient(180deg, var(--color-glow) 0%, transparent 58%),
    var(--color-bg);
  font: 400 16px/1.65 var(--font-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

img {
  height: auto;
}

svg {
  flex-shrink: 0;
}

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

button,
summary,
[role="tab"] {
  cursor: pointer;
}

button {
  border: 0;
}

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

p,
ul,
ol,
blockquote,
figure {
  margin-top: 0;
}

ul,
ol {
  padding-left: 1.25em;
}

nav ul,
.site-footer ul,
.clean-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--color-text);
  font-family: var(--font-display);
  text-wrap: balance;
}

h1,
.hero-title {
  margin-bottom: 24px;
  font-size: clamp(52px, 5vw, 68px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(34px, 4vw, 50px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.018em;
}

h3 {
  margin-bottom: 14px;
  font-size: clamp(22px, 2.3vw, 28px);
  font-weight: 750;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

h4 {
  margin-bottom: 10px;
  font-size: 18px;
  line-height: 1.35;
}

p {
  margin-bottom: 1em;
}

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

code {
  overflow-wrap: anywhere;
  color: var(--color-accent-dark);
}

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

hr {
  border: 0;
  border-top: 1px solid var(--color-border);
}

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

:focus-visible {
  border-radius: var(--radius-sm);
  outline: var(--focus-size) solid var(--color-accent);
  outline-offset: 3px;
}

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

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

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

.section-tight {
  padding-top: 64px;
  padding-bottom: 64px;
  overflow-x: clip;
}

.section-head {
  max-width: 780px;
  margin: 0 auto 48px;
  text-align: center;
}

.eyebrow,
.section-pill {
  display: inline-flex;
  min-height: 28px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  padding: 4px 12px;
  overflow: hidden;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.eyebrow::before,
.section-pill::before {
  width: 6px;
  height: 6px;
  flex: 0 0 6px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent), var(--color-apricot));
  content: "";
}

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

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

@supports (-webkit-background-clip: text) {
  .gradient-text {
    background: linear-gradient(100deg, var(--color-accent), var(--color-apricot));
    color: transparent;
    background-clip: text;
    -webkit-background-clip: text;
  }
}

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

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

.panel,
.card-shell {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-highlight), var(--shadow-card);
}

.panel {
  padding: 28px;
}

.card-shell {
  padding: 24px;
}

.badge,
.tag,
.fact-chip {
  display: inline-flex;
  min-height: 26px;
  max-width: 100%;
  align-items: center;
  gap: 7px;
  padding: 4px 10px;
  overflow: hidden;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.35;
}

.badge {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
}

.badge-accent,
.tag-accent {
  background: var(--color-accent);
  color: var(--color-on-accent);
}

.badge-success,
.tag-success {
  background: var(--color-success-tint);
  color: var(--color-success);
}

.badge-mist,
.tag-mist {
  background: var(--color-mist-tint);
  color: var(--color-muted);
}

.fact-chip {
  border: 1px solid var(--color-border);
  background: var(--color-panel-strong);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

.btn {
  display: inline-flex;
  min-height: 52px;
  min-width: 24px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 650;
  line-height: 1.2;
  text-align: center;
  transition: transform 150ms ease, box-shadow 150ms ease, background-color 150ms ease, border-color 150ms ease;
}

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

.btn-primary {
  border-color: var(--color-accent);
  background: linear-gradient(135deg, var(--color-accent), var(--color-apricot));
  color: var(--color-on-accent);
  box-shadow: var(--shadow-button), inset 0 1px 0 var(--color-white-inset);
}

.btn-primary:hover {
  box-shadow: 0 16px 30px -10px var(--color-shadow-accent-strong), inset 0 1px 0 var(--color-white-inset);
}

.btn-secondary {
  border-color: var(--color-border);
  background: var(--color-panel);
  color: var(--color-text);
  box-shadow: inset 0 1px 0 var(--color-highlight), 0 1px 2px var(--color-shadow-cool);
}

.btn-secondary:hover {
  border-color: var(--color-mist);
}

.btn-quiet {
  min-height: 42px;
  padding: 8px 18px;
  border-color: var(--color-accent);
  background: var(--color-panel);
  color: var(--color-accent);
}

.btn-quiet:hover {
  background: var(--color-accent);
  color: var(--color-on-accent);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.reveal {
  transition: opacity 560ms ease, transform 560ms ease;
}

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

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

.site-head {
  position: sticky;
  top: 0;
  z-index: 120;
  height: var(--header-height);
}

.site-head-inner {
  display: flex;
  width: 100%;
  height: var(--header-height);
  align-items: center;
  gap: 30px;
}

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

.site-brand img {
  width: 38px;
  height: 38px;
}

.site-brand-name {
  font: 750 20px/1 var(--font-display);
  letter-spacing: -0.02em;
}

.site-brand-local {
  color: var(--color-muted);
  font-size: 15px;
  font-weight: 500;
}

.desktop-nav {
  display: flex;
  flex: 1 1 auto;
  align-items: center;
  gap: 26px;
  margin-left: 18px;
}

.desktop-nav a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 520;
  transition: color 150ms ease;
}

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

.desktop-nav a.is-active {
  font-weight: 700;
}

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 12px;
}

.login-link {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  padding: 7px 18px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  color: var(--color-accent);
  font-size: 14px;
  font-weight: 700;
  transition: background-color 150ms ease, color 150ms ease, transform 150ms ease;
}

.login-link:hover {
  transform: translateY(-1px);
  background: var(--color-accent);
  color: var(--color-on-accent);
}

.language-picker {
  position: relative;
}

.language-toggle {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px;
  background: transparent;
  color: var(--color-muted);
  font-size: 14px;
}

.language-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 52;
  display: none;
  width: 150px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  box-shadow: var(--shadow-card);
}

.language-picker.is-open .language-menu {
  display: block;
}

.language-menu a {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
  font-size: 14px;
}

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

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

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: var(--radius-pill);
  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: fixed;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 50;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  padding: 12px var(--gutter) 24px;
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
  box-shadow: var(--shadow-card);
  overscroll-behavior: contain;
}

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

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 42px;
  align-items: center;
  padding: 6px 8px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  font-weight: 600;
}

.mobile-nav a.is-active {
  color: var(--color-accent);
}

.mobile-language-links {
  display: none;
}

.mobile-language-links strong {
  display: block;
  grid-column: 1 / -1;
  margin-bottom: 4px;
  color: var(--color-muted);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 35;
  display: none;
  background: var(--color-overlay);
}

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

.site-footer {
  overflow-x: clip;
  background: var(--color-footer);
  color: var(--color-on-accent);
}

.footer-main {
  display: grid;
  grid-template-columns: 1.25fr 1fr 1.25fr 0.8fr;
  gap: 44px;
  padding-top: 72px;
  padding-bottom: 52px;
}

.footer-brand {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}

.footer-brand img {
  width: 40px;
  height: 40px;
}

.footer-brand strong {
  font-size: 21px;
}

.footer-summary {
  max-width: 34em;
  color: var(--color-footer-muted);
  font-size: 14px;
}

.footer-col h2 {
  margin-bottom: 16px;
  color: var(--color-on-accent);
  font-size: 14px;
  font-weight: 750;
  letter-spacing: 0.06em;
}

.footer-col a {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  color: var(--color-footer-muted);
  font-size: 14px;
}

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

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

.footer-hot a {
  min-height: 30px;
  padding: 3px 9px;
  border: 1px solid var(--color-muted);
  border-radius: var(--radius-pill);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 20px;
  padding-bottom: 24px;
  border-top: 1px solid var(--color-muted);
  color: var(--color-footer-muted);
  font-size: 13px;
}

.footer-legal,
.footer-languages {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

#server-status {
  position: relative;
  display: block;
  width: 100%;
  max-width: 100%;
  margin-bottom: 40px;
  overflow: hidden;
}

#server-status + * {
  margin-top: 0;
}

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

.prose > * {
  max-width: 100%;
}

.prose p,
.prose li {
  color: var(--color-muted);
}

.prose h2 {
  margin-top: 64px;
}

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

.prose a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

.tilt,
.tilt-card {
  transform: rotate(-0.35deg);
}

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

@media (max-width: 1180px) {
  :root {
    --gutter: 28px;
  }

  .desktop-nav {
    gap: 17px;
    margin-left: 4px;
  }

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

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

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

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

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

  .footer-main {
    gap: 36px;
  }
}

@media (max-width: 768px) {
  :root {
    --section-space: 76px;
  }

  h1,
  .hero-title {
    font-size: clamp(32px, 9.5vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: clamp(29px, 7vw, 38px);
  }

  .section-head {
    margin-bottom: 36px;
  }

  .footer-main {
    grid-template-columns: 1fr;
    padding-top: 56px;
  }

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

@media (max-width: 640px) {
  :root {
    --gutter: 18px;
    --header-height: 64px;
  }

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

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

  .site-head,
  .site-head-inner {
    height: var(--header-height);
  }

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

  .site-brand img {
    width: 34px;
    height: 34px;
  }

  .site-brand-name {
    font-size: 18px;
  }

  .site-brand-local {
    display: none;
  }

  .header-tools {
    gap: 7px;
  }

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

  .mobile-nav {
    top: var(--header-height);
    max-width: 100%;
    padding-inline: var(--gutter);
  }

  .nav-veil {
    inset: var(--header-height) 0 0;
    max-width: 100%;
  }

  .panel,
  .card-shell {
    padding: 20px;
  }

  .button-row {
    width: 100%;
  }

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

  .tilt,
  .tilt-card {
    transform: none;
  }

  pre {
    padding: 16px;
  }
}

@media (max-width: 390px) {
  :root {
    --gutter: 16px;
  }

  .login-link {
    padding-inline: 11px;
    font-size: 13px;
  }

  .site-brand {
    gap: 7px;
  }

  .site-brand img {
    width: 32px;
    height: 32px;
  }
}

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

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

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