:root {
  --color-bg: #08211E;
  --color-panel: #0C2B27;
  --color-panel-raised: #113831;
  --color-border: #1E4A42;
  --color-accent: #4D82F2;
  --color-accent-dark: #2C5FD9;
  --color-text: #EAF4F0;
  --color-text-muted: #9EB5AD;
  --color-success: #3FD68F;
  --color-warn: #E8B24A;
  --color-error: #E86A5E;
  --color-line-strong: #C7DAD2;
  --color-line-soft: #7E968E;
  --color-flag-red: #CB3A31;
  --color-flag-blue: #20418F;
  --color-flag-white: #F4F6F8;
  --color-white: #FFFFFF;
  --color-transparent: transparent;
  --color-accent-glow: rgba(77, 130, 242, 0.3);
  --color-accent-mist: rgba(77, 130, 242, 0.07);
  --color-accent-water: rgba(77, 130, 242, 0.5);
  --color-accent-water-soft: rgba(77, 130, 242, 0.22);
  --color-accent-water-deep: rgba(44, 95, 217, 0.12);
  --color-edge-highlight: rgba(234, 244, 240, 0.07);
  --color-button-highlight: rgba(234, 244, 240, 0.28);
  --color-overlay: rgba(8, 33, 30, 0.84);
  --color-shadow: rgba(3, 14, 13, 0.42);
  --color-grid: rgba(158, 181, 173, 0.06);
  --font-display: "Inter", "Noto Sans SC", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Courier New", monospace;
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-pill: 999px;
  --header-height: 64px;
  --content-width: 1200px;
  --reading-width: 780px;
  --gutter: 36px;
  --section-space: 104px;
  --focus-width: 2px;
  --shadow-panel: 0 24px 60px var(--color-shadow);
  --transition-fast: 150ms ease;
  --transition-base: 260ms ease;
  --toc-offset: 84px;
}

*,
*::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: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

img,
svg,
video,
canvas {
  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;
}

a,
button,
summary,
[role="tab"],
[tabindex] {
  -webkit-tap-highlight-color: var(--color-transparent);
}

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

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

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

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

h1,
.hero-title {
  margin-bottom: 22px;
  font-size: clamp(52px, 5.4vw, 68px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(34px, 4vw, 48px);
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.18;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(22px, 2.5vw, 28px);
  font-weight: 750;
  line-height: 1.3;
}

h4 {
  margin-bottom: 8px;
  font-size: 18px;
}

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

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

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

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

code {
  overflow-wrap: anywhere;
}

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

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

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

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

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

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

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

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

.section-head {
  max-width: 760px;
  margin-bottom: 42px;
}

.section-head.centered {
  margin-inline: auto;
  text-align: center;
}

.eyebrow {
  margin-bottom: 12px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

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

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

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

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

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

.card {
  position: relative;
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  padding: 26px;
  box-shadow: inset 0 1px 0 var(--color-edge-highlight);
}

.card::before {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(135deg, var(--color-edge-highlight), var(--color-transparent) 42%);
  content: "";
  pointer-events: none;
}

.card > * {
  position: relative;
}

.badge,
.chip,
.tag {
  display: inline-flex;
  min-height: 28px;
  max-width: 100%;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-edge-highlight);
  padding: 5px 13px;
  color: var(--color-text-muted);
  font-size: 12px;
  line-height: 1.4;
}

.badge {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.badge-dot,
.status-dot {
  width: 7px;
  height: 7px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
}

.status-dot.success,
.chip-dot {
  background: var(--color-success);
}

.chip-dot {
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: var(--radius-pill);
}

.tag {
  overflow: hidden;
  justify-content: center;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.btn,
.button {
  display: inline-flex;
  min-width: 24px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  border: 1px solid var(--color-transparent);
  border-radius: var(--radius-sm);
  padding: 11px 28px;
  font-weight: 650;
  line-height: 1.3;
  text-align: center;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

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

.btn-primary {
  background: var(--color-accent);
  box-shadow: 0 10px 28px var(--color-accent-glow), inset 0 1px 0 var(--color-button-highlight);
  color: var(--color-text);
}

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

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

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

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

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

.btn svg,
.button svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.site-header {
  position: relative;
  z-index: 100;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

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

.site-brand {
  display: inline-flex;
  min-height: 44px;
  flex: none;
  align-items: center;
  gap: 10px;
}

.site-brand img {
  width: 26px;
  height: 26px;
  flex-shrink: 0;
}

.brand-word {
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

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

.desktop-nav {
  flex: 1;
  min-width: 0;
}

.desktop-nav ul {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
  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: 14px;
  opacity: 0.52;
}

.desktop-nav a {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  padding-inline: 1px;
  color: var(--color-text-muted);
  font-size: 14px;
  transition: color var(--transition-fast);
}

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

.desktop-nav a.is-active {
  font-weight: 650;
}

.header-tools {
  display: flex;
  flex: none;
  align-items: center;
  gap: 12px;
}

.language-menu {
  position: relative;
}

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

.language-toggle svg {
  width: 10px;
  flex-shrink: 0;
}

.language-popover {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 130;
  display: none;
  width: 164px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-panel);
  padding: 6px;
}

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

.language-popover a {
  display: flex;
  min-height: 40px;
  align-items: center;
  border-radius: var(--radius-xs);
  padding: 7px 10px;
  color: var(--color-text-muted);
  font-size: 13px;
}

.language-popover a:hover,
.language-popover a.is-current {
  background: var(--color-panel);
  color: var(--color-text);
}

.header-login {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel);
  box-shadow: inset 0 1px 0 var(--color-edge-highlight);
  padding: 7px 21px;
  color: var(--color-text);
  font-size: 14px;
  font-weight: 650;
}

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

.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-sm);
  background: var(--color-panel);
  padding: 9px;
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  width: 19px;
  height: 1px;
  background: var(--color-text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.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;
}

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

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::before {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::after {
  transform: translateY(-6px) rotate(-45deg);
}

.mobile-nav {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 120;
  display: none;
  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);
  padding: 12px var(--gutter) 20px;
}

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

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

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

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

.mobile-nav-languages {
  display: grid;
  gap: 0;
  margin-top: 12px;
}

.mobile-nav-languages strong {
  padding: 10px 4px 4px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 90;
  display: none;
  background: var(--color-overlay);
}

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

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

.footer-main {
  display: grid;
  grid-template-columns: minmax(250px, 1.35fr) repeat(3, minmax(150px, 1fr));
  gap: 48px;
  padding-top: 64px;
  padding-bottom: 44px;
}

.footer-brand p {
  max-width: 360px;
  margin-top: 18px;
  font-size: 14px;
}

.footer-title {
  margin-bottom: 16px;
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
}

.footer-links {
  display: grid;
  gap: 8px;
  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: 22px;
  border-top: 1px solid var(--color-border);
  padding-top: 20px;
  padding-bottom: 24px;
  color: var(--color-text-muted);
  font-size: 12px;
}

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

.footer-legal a {
  min-height: 24px;
}

.reveal {
  transition: opacity 600ms ease, transform 600ms ease;
}

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

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

.prose {
  max-width: 100%;
}

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

.prose h3 {
  margin-top: 38px;
}

.prose a:not(.btn):not(.button) {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose li + li {
  margin-top: 8px;
}

.prose blockquote {
  margin-inline: 0;
}

.prose table {
  border-collapse: collapse;
}

.prose > .data-table {
  display: block;
  min-width: 0;
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

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

@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: 76px;
  }

  h1,
  .hero-title {
    font-size: clamp(32px, 9.2vw, 40px);
    line-height: 1.12;
  }

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

  .language-toggle .language-label {
    display: none;
  }

  .footer-main {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 36px 24px;
  }

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

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

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

  .header-inner {
    gap: 10px;
  }

  .site-brand {
    gap: 8px;
  }

  .brand-word {
    font-size: 17px;
  }

  .header-tools {
    gap: 6px;
    margin-left: auto;
  }

  .header-login {
    min-height: 36px;
    padding-inline: 14px;
  }

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

  .section {
    padding-top: 68px;
    padding-bottom: 68px;
  }

  .section-compact {
    padding-top: 46px;
    padding-bottom: 46px;
  }

  .card {
    padding: 21px;
  }

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

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

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

@media (max-width: 390px) {
  .site-brand img {
    width: 24px;
    height: 24px;
  }

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

  .btn,
  .button {
    width: 100%;
  }
}

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

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

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