:root {
  --color-bg: #26111C;
  --color-panel: #311624;
  --color-panel-raised: #3C1C2D;
  --color-border: #4E2A3C;
  --color-accent: #7FE0C3;
  --color-accent-strong: #4FBFA0;
  --color-text: #F7EDF1;
  --color-text-muted: #C9A9B6;
  --color-success: #6FD9A8;
  --color-warning: #F0C36B;
  --color-error: #F07A7A;
  --color-button-text: #1C0C14;
  --color-arc: #6E3D55;
  --color-focus-shadow: rgba(127, 224, 195, .3);
  --color-accent-glow: rgba(127, 224, 195, .55);
  --color-accent-glow-soft: rgba(127, 224, 195, .22);
  --color-shadow: rgba(16, 6, 12, .55);
  --color-shadow-soft: rgba(16, 6, 12, .28);
  --color-overlay: rgba(38, 17, 28, .78);
  --color-flag-red: #D64545;
  --color-flag-blue: #3D5CA8;
  --color-flag-white: #F5EFF2;
  --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', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius-small: 6px;
  --radius-medium: 10px;
  --radius-large: 16px;
  --radius-pill: 999px;
  --shadow-panel: 0 24px 60px var(--color-shadow);
  --shadow-button: 0 10px 26px var(--color-focus-shadow);
  --header-height: 76px;
  --content-width: 1360px;
  --reading-width: 780px;
  --gutter: clamp(16px, 4vw, 40px);
  --section-space: clamp(72px, 9vw, 128px);
  --toc-offset: 96px;
  --transition-fast: 150ms ease;
  color-scheme: dark;
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
}

html.nav-open {
  overflow: hidden;
}

body {
  min-width: 320px;
  min-height: 100svh;
  margin: 0;
  overflow-x: clip;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.65;
  -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;
}

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

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

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

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

p {
  margin-bottom: 1.1em;
  color: var(--color-text-muted);
}

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

li + li {
  margin-top: .45rem;
}

h1,
h2,
h3,
h4 {
  margin-top: 0;
  color: var(--color-text);
  font-family: var(--font-display);
  line-height: 1.16;
  text-wrap: balance;
}

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5vw, 72px);
  font-weight: 900;
  letter-spacing: -.015em;
}

h2 {
  margin-bottom: 22px;
  font-size: clamp(34px, 4vw, 52px);
  font-weight: 850;
  letter-spacing: -.01em;
}

h3 {
  margin-bottom: 14px;
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 800;
}

h4 {
  margin-bottom: 10px;
  font-size: 18px;
  font-weight: 750;
}

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

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

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

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

hr {
  margin: 48px 0;
  border: 0;
  border-top: 1px solid var(--color-border);
}

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

:where(a, button, input, select, textarea, summary, [role="tab"]):focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

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

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

.text-link {
  text-decoration: underline;
  text-decoration-color: var(--color-accent-strong);
  text-underline-offset: 4px;
}

.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: clamp(48px, 6vw, 80px);
  padding-bottom: clamp(48px, 6vw, 80px);
  overflow-x: clip;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 44px;
}

.section-kicker {
  display: inline-block;
  margin-bottom: 14px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
}

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

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

.card {
  padding: 24px;
}

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

.btn {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 26px;
  border: 1px solid transparent;
  border-radius: var(--radius-medium);
  font-weight: 750;
  line-height: 1.2;
  text-align: center;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
}

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

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

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

.btn-ghost {
  border-color: var(--color-accent-strong);
  background: transparent;
  color: var(--color-accent);
}

.btn-small {
  min-height: 40px;
  padding: 8px 18px;
  font-size: 14px;
}

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

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

.badge,
.fact-chip {
  display: inline-flex;
  max-width: 100%;
  min-height: 28px;
  align-items: center;
  gap: 8px;
  padding: 5px 13px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 12px;
}

.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 9px var(--color-accent-glow);
}

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

.badge-warning .status-dot {
  background: var(--color-warning);
  box-shadow: none;
}

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

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

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

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

.header-inner {
  position: relative;
  display: flex;
  width: 100%;
  max-width: var(--content-width);
  height: 100%;
  align-items: center;
  gap: 28px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

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

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

.brand-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: .02em;
}

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

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.main-nav a {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  padding: 8px 15px;
  border-radius: var(--radius-pill);
  color: var(--color-text-muted);
  font-size: 14px;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.main-nav a:hover {
  color: var(--color-text);
}

.main-nav a.is-active {
  background: var(--color-panel-raised);
  color: var(--color-text);
  font-weight: 650;
}

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

.lang-control {
  position: relative;
}

.lang-button {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 6px 8px;
  border: 0;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 13px;
}

.lang-menu {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  z-index: 110;
  display: none;
  width: 170px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-panel);
}

.lang-menu.is-open {
  display: grid;
}

.lang-menu a {
  display: flex;
  min-height: 42px;
  align-items: center;
  padding: 8px 11px;
  border-radius: var(--radius-small);
  color: var(--color-text-muted);
}

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

.header-login {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  padding: 8px 19px;
  border: 1px solid var(--color-accent-strong);
  border-radius: var(--radius-medium);
  color: var(--color-accent);
  font-size: 14px;
  font-weight: 700;
}

.menu-toggle {
  display: none;
  width: 44px;
  min-width: 44px;
  height: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-medium);
  background: var(--color-panel);
  color: var(--color-text);
}

.menu-toggle svg {
  width: 20px;
  height: 20px;
}

.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;
  padding: 12px var(--gutter) 20px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel);
}

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

.mobile-nav a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  padding: 11px 12px;
  border-radius: var(--radius-small);
  color: var(--color-text-muted);
}

.mobile-nav a.is-active {
  background: var(--color-panel-raised);
  color: var(--color-text);
  font-weight: 700;
}

.mobile-languages {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--color-border);
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr 1.4fr 1fr;
  gap: 42px;
  padding-top: 58px;
  padding-bottom: 42px;
}

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

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

.footer-title {
  margin-bottom: 14px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 800;
}

.footer-links {
  display: grid;
  gap: 9px;
}

.footer-links a {
  min-height: 28px;
  color: var(--color-text-muted);
  font-size: 14px;
}

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

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

.footer-hot 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-text-muted);
  font-size: 12px;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 20px;
  padding-bottom: 26px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 13px;
}

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

.prose {
  font-size: 17px;
  line-height: 1.82;
}

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

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

.prose a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 4px;
}

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

.prose blockquote {
  margin-inline: 0;
}

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

@media (max-width: 1120px) {
  .main-nav {
    display: none;
  }

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

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

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

@media (max-width: 768px) {
  :root {
    --header-height: 68px;
  }

  h1 {
    font-size: clamp(32px, 9vw, 40px);
    line-height: 1.12;
  }

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

  .header-inner {
    gap: 10px;
  }

  .header-tools {
    margin-left: auto;
    gap: 7px;
  }

  .lang-control {
    display: none;
  }

  .header-login {
    min-height: 40px;
    padding-inline: 14px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }

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

  .prose {
    font-size: 16px;
  }
}

@media (max-width: 640px) {
  .wrap,
  .reading-wrap {
    padding-inline: var(--gutter);
  }

  .button-row {
    align-items: stretch;
    flex-direction: column;
  }

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

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

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

  .brand img {
    width: 25px;
    height: 25px;
  }
}

@media (max-width: 374px) {
  .header-login {
    padding-inline: 11px;
    font-size: 13px;
  }

  .brand {
    gap: 7px;
  }

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

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

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

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