:root {
  color-scheme: dark;
  --color-bg: #0E121B;
  --color-panel: #141A26;
  --color-panel-raised: #1B2231;
  --color-border: #283041;
  --color-accent: #A2F26B;
  --color-accent-dark: #63C23F;
  --color-text: #EEF1F6;
  --color-text-muted: #98A2B3;
  --color-success: #5FD6A0;
  --color-warning: #F5B94A;
  --color-error: #FF6B7A;
  --color-on-accent: #0E121B;
  --color-grid: rgba(238, 241, 246, .04);
  --color-glass: rgba(255, 255, 255, .06);
  --color-glass-edge: rgba(255, 255, 255, .12);
  --color-glass-highlight: rgba(255, 255, 255, .16);
  --color-edge-strong: rgba(255, 255, 255, .18);
  --color-accent-glow: rgba(162, 242, 107, .42);
  --color-accent-glow-soft: rgba(162, 242, 107, .22);
  --color-accent-shadow: rgba(162, 242, 107, .08);
  --color-accent-tint: rgba(162, 242, 107, .10);
  --color-accent-edge: rgba(162, 242, 107, .45);
  --color-curtain: rgba(162, 242, 107, .26);
  --color-shadow: rgba(3, 6, 12, .60);
  --color-mask: #000000;
  --color-flag-red: #D8323C;
  --color-flag-blue: #2B4C9B;
  --color-flag-white: #F4F6FA;
  --color-flag-edge: rgba(238, 241, 246, .14);
  --font-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Hiragino Sans', 'Apple SD Gothic Neo', 'Malgun Gothic', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Hiragino Sans', 'Apple SD Gothic Neo', 'Malgun Gothic', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
  --radius-xl: 24px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --radius-pill: 999px;
  --shadow-panel: 0 20px 44px -22px var(--color-shadow);
  --shadow-accent: 0 0 24px var(--color-accent-glow-soft);
  --content-width: 1240px;
  --reading-width: 760px;
  --gutter: 32px;
  --header-height: 72px;
  --focus-size: 2px;
  --toc-offset: 92px;
  --motion-fast: 150ms;
  --motion-base: 300ms;
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  -webkit-text-size-adjust: 100%;
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  overflow-wrap: break-word;
  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;
  background-image:
    linear-gradient(var(--color-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-grid) 1px, transparent 1px);
  background-size: 40px 40px;
  content: "";
  pointer-events: none;
}

main,
section,
article,
aside,
header,
footer,
nav,
div {
  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,
summary {
  cursor: pointer;
}

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

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

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

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

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

:not(pre) > code {
  padding: .15em .4em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel);
  color: var(--color-accent);
  font-size: .9em;
}

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

pre code {
  white-space: pre;
  overflow-wrap: normal;
}

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

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5.2vw, 72px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.012em;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(32px, 3.4vw, 48px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -.01em;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(21px, 2vw, 28px);
  font-weight: 800;
  line-height: 1.3;
}

p {
  margin-bottom: 1.15em;
  color: var(--color-text-muted);
}

strong {
  color: var(--color-text);
}

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

: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: 96px;
  padding-bottom: 96px;
}

.section-compact {
  padding-top: 64px;
  padding-bottom: 64px;
}

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

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

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

.gradient-text {
  background: linear-gradient(92deg, var(--color-accent), var(--color-success));
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 24px var(--color-accent-glow-soft));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.eyebrow,
.badge,
.tag {
  display: inline-flex;
  min-height: 28px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  padding: 3px 12px;
  overflow: hidden;
  border: 1px solid var(--color-glass-edge);
  border-radius: var(--radius-pill);
  background: var(--color-glass);
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 600;
  text-overflow: ellipsis;
}

.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 10px var(--color-accent-glow);
}

.badge-accent {
  border-color: var(--color-accent-edge);
  background: var(--color-accent-tint);
  color: var(--color-accent);
}

.btn,
.btn-primary,
.btn-secondary,
.btn-quiet {
  display: inline-flex;
  min-width: 24px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  transition:
    color var(--motion-fast) ease,
    background var(--motion-fast) ease,
    border-color var(--motion-fast) ease,
    box-shadow var(--motion-fast) ease,
    transform var(--motion-fast) ease;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-on-accent);
  box-shadow: var(--shadow-accent);
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  box-shadow: 0 0 28px var(--color-accent-glow);
  transform: translateY(-1px);
}

.btn-secondary {
  border-color: var(--color-edge-strong);
  background: var(--color-panel);
  color: var(--color-text);
}

.btn-secondary:hover {
  border-color: var(--color-accent-edge);
  background: var(--color-panel-raised);
}

.btn-quiet {
  padding-inline: 8px;
  color: var(--color-text);
}

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

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: .48;
  transform: none;
}

.arrow-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 8px;
  color: var(--color-text);
  font-weight: 700;
}

.arrow-link::after {
  content: "→";
  transition: transform var(--motion-fast) ease;
}

.arrow-link:hover {
  color: var(--color-accent);
}

.arrow-link:hover::after {
  transform: translateX(3px);
}

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

.glass-panel {
  border: 1px solid var(--color-glass-edge);
  border-radius: var(--radius-xl);
  background: var(--color-glass);
  box-shadow:
    inset 0 1px 0 var(--color-glass-highlight),
    var(--shadow-panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

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

.prose h2,
.prose h3 {
  margin-top: 1.8em;
  color: var(--color-text);
}

.prose a:not(.btn):not(.btn-primary):not(.btn-secondary) {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: var(--color-accent-edge);
  text-underline-offset: .2em;
}

.prose li {
  margin-bottom: .55em;
}

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

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

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

/* Shared header */
.site-head {
  position: relative;
  z-index: 70;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

.head-row {
  display: flex;
  height: var(--header-height);
  align-items: center;
  gap: 24px;
}

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

.brand img {
  width: 30px;
  height: 30px;
}

.brand-name {
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
}

.brand-local {
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 600;
}

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

.desktop-nav ul {
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.5vw, 25px);
}

.desktop-nav a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 550;
  white-space: nowrap;
}

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

.desktop-nav a.is-active {
  font-weight: 750;
}

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

.login-link {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  padding: 7px 18px;
  border: 1px solid var(--color-edge-strong);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text);
  font-size: 14px;
  font-weight: 700;
}

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

.language-control {
  position: relative;
}

.language-button {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 6px 8px;
  border: 0;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 13px;
}

.language-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 76;
  display: none;
  width: 160px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-panel);
}

.language-control.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-text-muted);
}

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

.menu-button {
  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-md);
  background: var(--color-panel);
  color: var(--color-text);
}

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

.mobile-nav {
  display: none;
}

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 44px;
  align-items: center;
  padding: 11px 16px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}

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

.mobile-nav .mobile-language-label {
  padding: 14px 16px 5px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
}

.nav-veil {
  display: none;
}

/* Shared footer */
.site-footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr 1fr .8fr;
  gap: 48px;
  padding-top: 64px;
  padding-bottom: 46px;
}

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

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

.footer-brand strong {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 900;
}

.footer-about {
  max-width: 30em;
  font-size: 14px;
}

.footer-title {
  margin-bottom: 14px;
  color: var(--color-text);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .06em;
}

.footer-links {
  margin: 0;
  padding: 0;
  list-style: none;
}

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

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 22px;
  padding-bottom: 28px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 13px;
}

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

#server-status {
  position: relative;
  display: block;
  width: 100%;
  margin-bottom: 32px;
  overflow: hidden;
}

#server-status + * {
  margin-top: 32px;
}

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

@media (max-width: 1100px) {
  .desktop-nav {
    display: none;
  }

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

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

  .mobile-nav {
    position: absolute;
    top: var(--header-height);
    right: 0;
    left: 0;
    z-index: 75;
    max-height: calc(100dvh - var(--header-height));
    padding: 12px var(--gutter) 22px;
    overflow-y: auto;
    border-top: 1px solid var(--color-border);
    background: var(--color-bg);
    overscroll-behavior: contain;
  }

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

  .nav-veil {
    position: fixed;
    z-index: 65;
    inset: var(--header-height) 0 0;
    background: var(--color-shadow);
  }

  .site-head.is-menu-open + .nav-veil,
  .nav-veil.is-open {
    display: block;
  }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

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

  h1 {
    font-size: clamp(32px, 9.8vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: clamp(28px, 7vw, 36px);
  }

  .section {
    padding-top: 72px;
    padding-bottom: 72px;
  }

  .language-control {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

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

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

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

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

  .head-row {
    gap: 10px;
  }

  .brand-local {
    display: none;
  }

  .login-link {
    padding-inline: 14px;
  }

  .btn,
  .btn-primary,
  .btn-secondary {
    max-width: 100%;
  }

  .decorative-halo,
  .stripe-halo {
    max-width: 100%;
    transform: none;
  }
}

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

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

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