:root {
  --color-bg: #E4EDF6;
  --color-panel: #F4F9FD;
  --color-panel-strong: #D8E5F1;
  --color-border: #B9CCDE;
  --color-accent: #BE3455;
  --color-accent-dark: #93253F;
  --color-text: #22303E;
  --color-muted: #5B6E80;
  --color-success: #2E8B62;
  --color-warning: #C98A1B;
  --color-error: #A93226;
  --color-white: #FFFFFF;
  --color-transparent: transparent;
  --color-shadow-soft: rgba(34, 48, 62, 0.05);
  --color-shadow-mid: rgba(34, 48, 62, 0.1);
  --color-shadow-deep: rgba(34, 48, 62, 0.16);
  --color-accent-halo: rgba(190, 52, 85, 0.09);
  --color-veil: rgba(34, 48, 62, 0.42);
  --font-display: Georgia, "Iowan Old Style", "Palatino Linotype", "Noto Serif SC", "Source Han Serif SC", "Songti SC", SimSun, serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Courier New", monospace;
  --radius-xl: 26px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 9px;
  --radius-pill: 999px;
  --shadow-card: 0 32px 64px var(--color-shadow-deep), 0 10px 22px var(--color-shadow-mid);
  --shadow-tile: 0 2px 6px var(--color-shadow-soft);
  --shadow-hover: 0 14px 30px var(--color-shadow-mid);
  --page-max: 1368px;
  --reading-max: 820px;
  --gutter: 40px;
  --header-height: 70px;
  --toc-offset: 86px;
  --transition-fast: 150ms ease;
  --transition-reveal: 620ms cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::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: 1.65;
  text-rendering: optimizeLegibility;
}

body,
button,
input,
select,
textarea {
  font-family: var(--font-body);
}

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

img {
  height: auto;
}

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

button,
summary,
select {
  cursor: pointer;
}

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

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

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

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

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

:not(pre) > code {
  padding: 0.12em 0.38em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel-strong);
}

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

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

hr {
  height: 1px;
  margin: 34px 0;
  border: 0;
  background: var(--color-border);
}

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

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

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

.section {
  padding-top: 76px;
  padding-bottom: 76px;
}

.section-compact {
  padding-top: 42px;
  padding-bottom: 42px;
}

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

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

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

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

.display-title,
h1,
h2 {
  font-family: var(--font-display);
  font-weight: 400;
  text-wrap: balance;
}

h1,
.display-title {
  margin-bottom: 20px;
  font-size: clamp(52px, 5vw, 72px);
  line-height: 1.12;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(34px, 3.3vw, 50px);
  line-height: 1.18;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.3;
}

.lead {
  max-width: 720px;
  color: var(--color-muted);
  font-size: clamp(17px, 1.6vw, 20px);
  line-height: 1.75;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  align-self: flex-start;
  gap: 7px;
  max-width: 100%;
  padding: 5px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  color: var(--color-muted);
  font-size: 12.5px;
  letter-spacing: 0.04em;
}

.eyebrow > svg,
.icon-fixed,
.flag-icon {
  flex-shrink: 0;
}

.btn,
.btn-primary,
.btn-secondary,
.btn-ghost,
.btn-login {
  display: inline-flex;
  min-width: 24px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 24px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-text);
  font-weight: 600;
  line-height: 1.2;
  text-align: center;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast);
}

.btn:hover,
.btn-secondary:hover,
.btn-ghost:hover {
  border-color: var(--color-muted);
  background: var(--color-panel-strong);
  transform: translateY(-1px);
}

.btn-primary {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: var(--color-white);
  box-shadow: 0 10px 22px var(--color-accent-halo);
}

.btn-primary:hover {
  border-color: var(--color-accent-dark);
  background: var(--color-accent-dark);
  transform: translateY(-1px);
}

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

.btn-login {
  min-height: 40px;
  padding: 8px 20px;
  border: 2px solid var(--color-accent);
  background: var(--color-transparent);
  color: var(--color-accent);
  font-size: 13.5px;
}

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

.btn[aria-disabled="true"],
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

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

.panel,
.card {
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-panel);
  box-shadow: var(--shadow-tile);
}

.panel-strong {
  background: var(--color-panel-strong);
}

.card {
  padding: 28px;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.badge,
.capsule,
.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-bg);
  color: var(--color-text);
  font-size: 12.5px;
  line-height: 1.4;
  text-overflow: ellipsis;
}

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

.badge-success {
  border-color: var(--color-success);
  color: var(--color-success);
}

.status-dot {
  width: 9px;
  height: 9px;
  flex: 0 0 9px;
  border-radius: var(--radius-pill);
  background: var(--color-success);
}

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

.head-in {
  width: 100%;
  max-width: var(--page-max);
  min-height: var(--header-height);
  margin-inline: auto;
  padding: 12px var(--gutter);
  display: flex;
  align-items: center;
  gap: 24px;
}

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

.brand-logo {
  width: 30px;
  height: 30px;
  flex: none;
}

.brand-name {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

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

.main-nav {
  display: flex;
  min-width: 0;
  align-items: center;
  gap: 3px;
  flex: 1;
}

.main-nav a {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  gap: 6px;
  padding: 7px 9px;
  border-radius: var(--radius-pill);
  color: var(--color-muted);
  font-size: 13px;
  white-space: nowrap;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.main-nav a svg {
  width: 15px;
  height: 15px;
  flex: none;
}

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

.main-nav a.is-active {
  border: 1px solid var(--color-border);
  padding: 6px 9px;
}

.head-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

.language-menu {
  position: relative;
}

.language-toggle,
.menu-toggle {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 7px 10px;
  border: 0;
  border-radius: var(--radius-pill);
  background: var(--color-transparent);
  color: var(--color-muted);
}

.language-popover {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 80;
  width: 170px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel);
  box-shadow: var(--shadow-hover);
}

.language-popover[hidden] {
  display: none;
}

.language-popover a {
  display: flex;
  min-height: 42px;
  align-items: center;
  padding: 8px 11px;
  border-radius: var(--radius-sm);
}

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

.menu-toggle {
  display: none;
  border: 1px solid var(--color-border);
}

.menu-toggle svg {
  width: 21px;
  height: 21px;
}

.mobile-nav {
  display: none;
}

.mobile-veil {
  display: none;
}

.site-footer {
  margin-top: 70px;
  border-top: 1px solid var(--color-border);
  background: var(--color-panel-strong);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(240px, 1.35fr) repeat(3, minmax(150px, 1fr));
  gap: 42px;
  padding-top: 58px;
  padding-bottom: 42px;
}

.footer-brand p {
  max-width: 390px;
  margin-top: 16px;
  color: var(--color-muted);
}

.footer-title {
  margin-bottom: 14px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
}

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

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

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

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 16px;
  padding-top: 20px;
  padding-bottom: 26px;
  border-top: 1px solid var(--color-border);
  color: var(--color-muted);
  font-size: 13px;
}

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

.reveal {
  transition: opacity var(--transition-reveal), transform var(--transition-reveal);
}

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

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

.counter-stat {
  display: inline-block;
  min-width: 4ch;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.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: 14px 0;
  will-change: transform;
}

.ticker-group {
  display: flex;
  align-items: center;
  gap: 34px;
  flex: none;
}

.ticker-item {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: var(--color-muted);
  white-space: nowrap;
}

.decor-zone {
  position: relative;
  overflow-x: clip;
}

.prose {
  min-width: 0;
}

.prose h2,
.prose h3 {
  scroll-margin-top: var(--toc-offset);
}

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

.prose a:not(.btn):not(.btn-primary):not(.btn-secondary) {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

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

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

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

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

  .main-nav {
    gap: 1px;
  }

  .main-nav a {
    padding-inline: 7px;
    font-size: 12.5px;
  }

  .main-nav a.is-active {
    padding-inline: 7px;
  }

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

@media (max-width: 960px) {
  .main-nav,
  .language-popover {
    display: none;
  }

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

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

  .language-toggle {
    border: 1px solid var(--color-border);
  }

  .mobile-veil {
    position: fixed;
    inset: var(--header-height) 0 0;
    z-index: 54;
    background: var(--color-veil);
  }

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

  .mobile-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    z-index: 56;
    max-height: calc(100dvh - var(--header-height));
    padding: 12px var(--gutter) 22px;
    overflow-y: auto;
    overscroll-behavior: contain;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-panel);
    box-shadow: var(--shadow-hover);
  }

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

  .mobile-nav ul {
    display: grid;
    gap: 3px;
    margin: 0;
    padding: 0;
    list-style: none;
  }

  .mobile-nav a {
    display: flex;
    width: 100%;
    min-height: 46px;
    align-items: center;
    gap: 10px;
    padding: 11px 12px;
    border-radius: var(--radius-md);
    color: var(--color-text);
  }

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

  .mobile-nav a svg {
    width: 17px;
    height: 17px;
    flex: none;
  }

  .mobile-language {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--color-border);
  }

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

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --header-height: 66px;
  }

  h1,
  .display-title {
    font-size: clamp(34px, 9.5vw, 40px);
    line-height: 1.14;
  }

  h2 {
    font-size: clamp(29px, 8vw, 38px);
  }

  .section {
    padding-top: 58px;
    padding-bottom: 58px;
  }

  .head-in {
    gap: 12px;
    padding-block: 10px;
  }

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

  .btn-login {
    padding-inline: 15px;
  }

  .footer-grid {
    gap: 30px;
  }
}

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

  body {
    font-size: 14.5px;
  }

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

  .button-row,
  .cta-row {
    align-items: stretch;
  }

  .button-row .btn,
  .button-row .btn-primary,
  .button-row .btn-secondary,
  .cta-row .btn,
  .cta-row .btn-primary,
  .cta-row .btn-secondary {
    flex: 1 1 150px;
  }

  .card {
    padding: 22px;
  }

  .language-toggle {
    display: none;
  }

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

  .footer-bottom {
    display: grid;
  }
}

@media (max-width: 390px) {
  .brand-name {
    font-size: 16px;
  }

  .head-tools {
    gap: 6px;
  }

  .btn-login {
    min-width: 62px;
    padding-inline: 12px;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0s !important;
    animation-duration: 0s !important;
    animation-iteration-count: 1 !important;
  }

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

  .ticker-track {
    width: auto;
    flex-wrap: wrap;
    transform: none !important;
  }
}