:root {
  --color-bg: #1e130c;
  --color-panel: #291a11;
  --color-panel-raised: #362417;
  --color-border: #4d3823;
  --color-accent: #6fa1ff;
  --color-accent-deep: #3d6fd9;
  --color-wine: #7a3b47;
  --color-text: #f3eae0;
  --color-muted: #b9a68f;
  --color-success: #6fc48f;
  --color-warning: #e8b45a;
  --color-error: #e06a5e;
  --color-cream: #efe3d3;
  --color-white: #ffffff;
  --color-black: #000000;
  --color-shadow: rgba(0, 0, 0, 0.35);
  --color-shadow-deep: rgba(0, 0, 0, 0.55);
  --color-cream-grid: rgba(239, 227, 211, 0.055);
  --color-cream-grid-soft: rgba(239, 227, 211, 0.045);
  --color-cream-dot: rgba(239, 227, 211, 0.09);
  --color-panel-translucent: rgba(41, 26, 17, 0.6);
  --color-bg-translucent: rgba(30, 19, 12, 0.35);
  --color-highlight: rgba(111, 161, 255, 0.12);
  --color-wine-soft: rgba(122, 59, 71, 0.28);
  --color-success-soft: rgba(111, 196, 143, 0.14);
  --color-focus-shadow: rgba(111, 161, 255, 0.2);
  --flag-red: #c8382f;
  --flag-red-bright: #df3c3c;
  --flag-blue: #2b3f8c;
  --flag-white: #f5f2ec;
  --flag-black: #26221e;
  --flag-gold: #e0b23c;
  --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, "Liberation Mono", monospace;
  --radius-xs: 5px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-pill: 999px;
  --header-height: 64px;
  --content-width: 1240px;
  --reading-width: 780px;
  --gutter: 32px;
  --section-space: 104px;
  --section-space-small: 72px;
  --focus-ring: 2px solid var(--color-accent);
  --shadow-panel: inset 0 1px 0 rgba(243, 234, 224, 0.05), 0 6px 16px var(--color-shadow), 0 28px 56px -24px var(--color-shadow-deep);
  --shadow-lift: 0 18px 40px -24px var(--color-shadow-deep);
  --toc-offset: 82px;
}

*,
*::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: 15px;
  line-height: 1.68;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

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

img {
  height: auto;
}

svg {
  flex-shrink: 0;
}

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

button {
  border: 0;
}

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

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

p {
  margin-bottom: 1.15em;
}

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

li + li {
  margin-top: 0.45em;
}

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

h1 {
  max-width: 13em;
  margin-bottom: 20px;
  font-size: clamp(52px, 5.25vw, 72px);
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.12;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(34px, 4vw, 54px);
  font-weight: 800;
  letter-spacing: -0.012em;
  line-height: 1.16;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(21px, 2vw, 28px);
  font-weight: 750;
  line-height: 1.3;
}

h4 {
  margin-bottom: 8px;
  font-size: 17px;
  font-weight: 750;
}

strong {
  color: var(--color-text);
  font-weight: 700;
}

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

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

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

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

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

hr {
  height: 1px;
  margin: 40px 0;
  border: 0;
  background: var(--color-border);
}

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

:where(a, button, input, select, textarea, summary, [role="tab"]):focus-visible {
  outline: var(--focus-ring);
  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: var(--section-space);
  padding-bottom: var(--section-space);
  overflow-x: clip;
}

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

.section-panel {
  border-block: 1px solid var(--color-border);
  background: var(--color-panel);
}

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

.text-accent,
.h1-accent {
  background: linear-gradient(120deg, var(--color-accent) 20%, var(--color-accent-deep) 90%);
  background-clip: text;
  color: transparent;
  -webkit-background-clip: text;
}

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

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

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 14px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-accent);
  content: "";
}

.lead {
  max-width: 42em;
  color: var(--color-muted);
  font-size: clamp(17px, 1.8vw, 21px);
  line-height: 1.7;
}

.btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 15.5px;
  font-weight: 750;
  line-height: 1.2;
  text-align: center;
  transition: transform 180ms ease, color 180ms ease, background-color 180ms ease, border-color 180ms ease;
}

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

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

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

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

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

.btn-wine {
  background: var(--color-wine);
  color: var(--color-text);
}

.btn-small {
  min-height: 40px;
  padding: 9px 18px;
  font-size: 13.5px;
}

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.52;
  transform: none;
}

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

.badge,
.chip,
.tag {
  display: inline-flex;
  max-width: 100%;
  min-height: 28px;
  align-items: center;
  gap: 7px;
  padding: 4px 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel-translucent);
  color: var(--color-muted);
  font-size: 12.5px;
  line-height: 1.35;
}

.badge {
  border-color: transparent;
  background: var(--color-wine);
  color: var(--color-text);
}

.badge-dot::before,
.chip-dot::before {
  width: 6px;
  height: 6px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-success);
  content: "";
}

.tag {
  min-height: 25px;
  padding: 3px 10px;
  color: var(--color-cream);
  font-family: var(--font-mono);
  font-size: 11px;
}

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

.panel {
  padding: clamp(22px, 3vw, 36px);
}

.card {
  padding: 24px;
}

.card-raised {
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-lift);
}

.card > :last-child,
.panel > :last-child {
  margin-bottom: 0;
}

.reveal {
  transition: opacity 620ms ease, transform 620ms ease;
}

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

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

.site-header {
  position: relative;
  z-index: 60;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
}

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

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

.site-brand img {
  display: block;
  width: 30px;
  height: 30px;
}

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

.site-brand-local {
  color: var(--color-muted);
  font-weight: 550;
}

.desktop-nav {
  display: flex;
  height: var(--header-height);
  flex: 1;
  align-items: stretch;
}

.desktop-nav a {
  position: relative;
  display: flex;
  min-height: 44px;
  align-items: center;
  padding-inline: 9px;
  color: var(--color-muted);
  font-size: 13px;
  white-space: nowrap;
  transition: color 180ms ease;
}

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

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

.desktop-nav a.is-active::after {
  position: absolute;
  right: 9px;
  bottom: -1px;
  left: 9px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  content: "";
}

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

.language-menu {
  position: relative;
}

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

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

.language-toggle:hover,
.menu-toggle:hover {
  color: var(--color-text);
}

.language-list {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 75;
  display: none;
  width: 168px;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-panel);
}

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

.language-list a {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding: 8px 10px;
  border-radius: var(--radius-xs);
  color: var(--color-muted);
}

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

.header-login {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  justify-content: center;
  padding: 7px 17px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  font-size: 13.5px;
  font-weight: 700;
  transition: color 180ms ease, background-color 180ms ease;
}

.header-login:hover {
  background: var(--color-accent);
  color: var(--color-bg);
}

.menu-toggle {
  display: none;
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: currentColor;
  transition: transform 180ms ease, opacity 180ms ease;
}

.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: 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: 70;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel);
  overscroll-behavior: contain;
}

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

.mobile-nav-inner {
  padding: 8px var(--gutter) 18px;
}

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  padding: 11px 4px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-muted);
}

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

.mobile-language-title {
  margin: 18px 0 5px;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
}

.mobile-language-links a {
  min-height: 44px;
}

.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 50;
  display: none;
  background: var(--color-shadow-deep);
}

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

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

.footer-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr 1.25fr 0.8fr;
  gap: 44px;
  padding-top: 58px;
  padding-bottom: 46px;
}

.footer-brand {
  display: 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: 19px;
}

.footer-copy {
  max-width: 28em;
  color: var(--color-muted);
}

.footer-title {
  margin-bottom: 14px;
  color: var(--color-cream);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.footer-links {
  display: grid;
  gap: 8px;
}

.footer-links a {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  color: var(--color-muted);
  font-size: 13.5px;
}

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

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

.footer-keywords a {
  display: inline-flex;
  min-height: 30px;
  align-items: center;
  padding: 4px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-muted);
  font-size: 12px;
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 20px;
  padding-bottom: 24px;
  border-top: 1px solid var(--color-border);
  color: var(--color-muted);
  font-size: 12.5px;
}

.footer-legal,
.footer-languages {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

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

.prose {
  color: var(--color-muted);
  font-size: 16px;
}

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

.prose h2 {
  margin-top: 2.1em;
}

.prose h3 {
  margin-top: 1.75em;
}

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

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

.prose ol.steps {
  padding: 0;
  list-style: none;
  counter-reset: guide-step;
}

.prose ol.steps > li {
  position: relative;
  min-height: 42px;
  padding-left: 52px;
  counter-increment: guide-step;
}

.prose ol.steps > li::before {
  position: absolute;
  top: 0;
  left: 0;
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-accent);
  border-radius: 50%;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 12px;
  content: counter(guide-step);
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: calc(var(--toc-offset) + 18px);
}

.motion-ticker {
  max-width: 100%;
  overflow: hidden;
  border-block: 1px solid var(--color-border);
  background: var(--color-panel);
}

.ticker-track {
  display: flex;
  width: max-content;
  align-items: center;
  gap: 34px;
  padding-block: 15px;
  will-change: transform;
}

.ticker-item {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  flex-shrink: 0;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 12px;
  white-space: nowrap;
}

.ticker-item::before {
  width: 5px;
  height: 5px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-accent);
  content: "";
}

@media (max-width: 1180px) {
  .site-header-inner {
    gap: 16px;
  }

  .desktop-nav a {
    padding-inline: 6px;
    font-size: 12.5px;
  }

  .desktop-nav a.is-active::after {
    right: 6px;
    left: 6px;
  }

  .language-toggle {
    font-size: 0;
  }

  .language-toggle::before {
    font-size: 15px;
    content: "文";
  }
}

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

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

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

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

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --section-space: 76px;
    --section-space-small: 54px;
  }

  h1 {
    max-width: 100%;
    font-size: clamp(32px, 9.6vw, 40px);
    line-height: 1.12;
  }

  h2 {
    font-size: clamp(28px, 8vw, 38px);
  }

  .footer-grid {
    gap: 34px;
  }

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

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

  .section,
  .section-compact {
    overflow-x: clip;
  }

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

  .motion-ticker {
    overflow: visible;
  }

  .ticker-track {
    width: 100%;
    flex-wrap: wrap;
    gap: 10px 18px;
    padding: 14px 16px;
    transform: none !important;
  }

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

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

  .header-login {
    min-width: 56px;
    padding-inline: 12px;
  }

  .site-brand-name {
    font-size: 16px;
  }

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

  .footer-languages,
  .footer-legal {
    gap: 10px 14px;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto;
  }

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

  .btn,
  .desktop-nav a,
  .header-login,
  .menu-toggle-lines,
  .menu-toggle-lines::before,
  .menu-toggle-lines::after {
    transition: none;
  }
}