:root {
  --color-bg: #FFFFFF;
  --color-panel: #F7F8FA;
  --color-panel-strong: #EFF1F4;
  --color-border: #E4E7EC;
  --color-dot: #E9EBF0;
  --color-accent: #E4265E;
  --color-accent-dark: #B01A47;
  --color-text: #12141A;
  --color-muted: #5B616E;
  --color-success: #14A05A;
  --color-warning: #E8930C;
  --color-error: #D9302C;
  --color-white: #FFFFFF;
  --color-flag-red: #CE2939;
  --color-flag-navy: #27346A;
  --color-flag-gold: #F2C500;
  --color-flag-black: #1C1C22;
  --color-flag-blue: #244C9A;
  --color-focus-soft: rgba(228, 38, 94, 0.18);
  --color-shadow-soft: rgba(18, 20, 26, 0.06);
  --color-shadow-mid: rgba(18, 20, 26, 0.16);
  --color-shadow-button: rgba(18, 20, 26, 0.5);
  --color-overlay: rgba(18, 20, 26, 0.36);

  --font-display: 'Inter', 'Noto Sans SC', -apple-system, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', -apple-system, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', 'Menlo', Consolas, 'Courier New', monospace;

  --radius-pill: 999px;
  --radius-window: 22px;
  --radius-card: 12px;
  --radius-panel: 18px;
  --radius-menu: 14px;
  --radius-control: 10px;

  --shadow-window: 0 30px 70px -32px var(--color-shadow-mid), 0 6px 18px -6px var(--color-shadow-soft);
  --shadow-menu: 0 18px 44px -18px var(--color-shadow-mid);
  --shadow-button: 0 12px 26px -14px var(--color-shadow-button);
  --shadow-card: 0 18px 44px -30px var(--color-shadow-mid);

  --site-width: 1200px;
  --reading-width: 780px;
  --gutter: 32px;
  --header-height: 66px;
  --section-space: 104px;
  --focus-width: 2px;
  --transition-fast: 160ms ease;
  --transition-base: 260ms ease;
}

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

html {
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
}

html.nav-open {
  overflow: hidden;
}

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

img,
video,
canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

svg {
  flex-shrink: 0;
}

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

button,
summary {
  cursor: pointer;
}

button {
  margin: 0;
}

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

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

ul,
ol {
  padding-left: 1.3em;
}

nav ul,
.footer-links,
.trust-row,
.platform-row,
.flag-list,
.card-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

code,
kbd,
samp {
  font-family: var(--font-mono);
  font-size: 0.92em;
}

:not(pre) > code {
  max-width: 100%;
  padding: 0.16em 0.42em;
  overflow-wrap: anywhere;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-control);
  background: var(--color-panel);
}

pre {
  max-width: 100%;
  padding: 20px;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  background: var(--color-text);
  color: var(--color-bg);
  line-height: 1.65;
  tab-size: 2;
  -webkit-overflow-scrolling: touch;
}

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

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

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

a,
button,
summary,
input,
select,
textarea,
[role='tab'] {
  -webkit-tap-highlight-color: transparent;
}

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

.wrap,
.shell {
  width: 100%;
  max-width: var(--site-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: 64px;
  padding-bottom: 64px;
  overflow-x: clip;
}

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

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

.eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-muted);
}

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

h1 {
  margin-bottom: 22px;
  font-size: clamp(52px, 5.4vw, 72px);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(34px, 4vw, 50px);
  font-weight: 850;
  line-height: 1.14;
  letter-spacing: -0.018em;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(22px, 2.4vw, 28px);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.012em;
}

h4 {
  margin-bottom: 10px;
  font-size: 18px;
  font-weight: 750;
  line-height: 1.35;
}

.lead {
  max-width: 720px;
  color: var(--color-muted);
  font-size: clamp(18px, 2vw, 21px);
  line-height: 1.7;
}

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

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

.accent-word {
  position: relative;
  display: inline-block;
  padding: 0 0.05em 0.06em 0.02em;
  color: var(--color-accent);
  font-style: italic;
}

.accent-word::after {
  position: absolute;
  right: 0.06em;
  bottom: -0.015em;
  left: 0.02em;
  height: 0.085em;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  content: '';
}

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

.btn {
  display: inline-flex;
  min-width: 24px;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 14px 30px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 750;
  line-height: 1;
  text-align: center;
  transition: transform var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
}

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

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

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

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

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

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

.btn-small {
  min-height: 40px;
  padding: 11px 20px;
  font-size: 14px;
}

.btn-disabled,
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.48;
  transform: none;
}

.badge,
.tag,
.fact-pill {
  display: inline-flex;
  max-width: 100%;
  min-height: 28px;
  align-items: center;
  gap: 8px;
  padding: 5px 12px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  color: var(--color-muted);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.35;
}

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

.badge-dark {
  border-color: var(--color-text);
  background: var(--color-text);
  color: var(--color-bg);
}

.status-dot {
  width: 7px;
  height: 7px;
  flex: none;
  border-radius: 50%;
  background: var(--color-accent);
}

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

.panel {
  padding: clamp(22px, 4vw, 40px);
}

.card {
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.card-flat {
  box-shadow: none;
}

.dot-grid {
  position: relative;
  overflow-x: clip;
  background-color: var(--color-bg);
  background-image: radial-gradient(circle at 1px 1px, var(--color-dot) 1px, transparent 1.6px);
  background-size: 26px 26px;
}

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

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

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

[data-motion-counter] {
  display: inline-block;
  min-width: 3ch;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

[data-parallax-decor] {
  will-change: transform;
}

.tilt,
.tilt-card {
  transform: rotate(-0.45deg);
  transform-origin: center;
}

.site-header {
  position: relative;
  z-index: 50;
  border-bottom: 1px solid transparent;
  background: var(--color-bg);
}

.header-inner {
  display: flex;
  min-height: var(--header-height);
  align-items: center;
  gap: 28px;
}

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

.brand-logo {
  width: 28px;
  height: 28px;
  flex: none;
}

.brand-copy {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
}

.brand-name {
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 850;
  letter-spacing: -0.02em;
}

.brand-local {
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 600;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 12px;
}

.desktop-nav > a,
.more-toggle {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  gap: 6px;
  padding: 8px 15px;
  border: 0;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-muted);
  font-size: 15px;
  font-weight: 650;
  line-height: 1;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.desktop-nav > a:hover,
.more-toggle:hover,
.desktop-nav > a.is-active,
.more.is-active > .more-toggle {
  background: var(--color-panel);
  color: var(--color-text);
}

.more {
  position: relative;
}

.more-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  display: none;
  width: 196px;
  padding-top: 10px;
  transform: translateX(-50%);
}

.more:hover .more-menu,
.more:focus-within .more-menu,
.more.is-open .more-menu {
  display: block;
}

.more-card {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-menu);
  background: var(--color-bg);
  box-shadow: var(--shadow-menu);
}

.more-card a {
  display: flex;
  min-height: 42px;
  align-items: center;
  padding: 9px 14px;
  border-radius: var(--radius-control);
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 550;
}

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

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

.language-switch {
  position: relative;
}

.language-toggle {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  gap: 6px;
  padding: 8px 8px;
  border: 0;
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 550;
}

.language-toggle:hover {
  background: var(--color-panel);
  color: var(--color-text);
}

.language-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  display: none;
  width: 168px;
  padding: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-menu);
  background: var(--color-bg);
  box-shadow: var(--shadow-menu);
}

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

.language-menu a {
  display: flex;
  min-height: 42px;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  border-radius: var(--radius-control);
  color: var(--color-muted);
  font-size: 14px;
}

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

.login-button {
  display: inline-flex;
  min-width: 76px;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  padding: 9px 22px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
  font-weight: 700;
}

.login-button:hover {
  border-color: var(--color-muted);
  background: var(--color-panel);
}

.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-pill);
  background: var(--color-bg);
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-text);
  transition: transform 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: transparent;
}

.menu-toggle[aria-expanded='true'] .menu-toggle-lines::before {
  top: 0;
  transform: rotate(45deg);
}

.menu-toggle[aria-expanded='true'] .menu-toggle-lines::after {
  top: 0;
  transform: rotate(-45deg);
}

.mobile-nav {
  display: none;
}

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

.mobile-nav-panel {
  position: absolute;
  z-index: 54;
  top: 100%;
  right: 0;
  left: 0;
  max-height: calc(100dvh - var(--header-height));
  padding: 12px var(--gutter) 24px;
  overflow-y: auto;
  overscroll-behavior: contain;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
  box-shadow: var(--shadow-menu);
}

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

.mobile-nav-list a,
.mobile-language-list a {
  display: flex;
  width: 100%;
  min-height: 48px;
  align-items: center;
  justify-content: space-between;
  padding: 11px 10px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  font-size: 16px;
  font-weight: 650;
}

.mobile-nav-list a.is-active,
.mobile-language-list a[aria-current='true'] {
  color: var(--color-accent-dark);
}

.mobile-language-title {
  margin: 20px 10px 6px;
  color: var(--color-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

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

.nav-veil {
  position: fixed;
  z-index: 45;
  inset: var(--header-height) 0 0;
  display: none;
  border: 0;
  background: var(--color-overlay);
}

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

.site-footer {
  margin-top: 80px;
  border-top: 1px solid var(--color-border);
  background: var(--color-panel);
}

.footer-main {
  display: grid;
  grid-template-columns: 1.35fr 1fr 1fr 0.8fr;
  gap: 44px;
  padding-top: 62px;
  padding-bottom: 48px;
}

.footer-brand {
  max-width: 350px;
}

.footer-brand .brand {
  margin-bottom: 18px;
}

.footer-intro {
  margin: 0;
  color: var(--color-muted);
  font-size: 14px;
  line-height: 1.75;
}

.footer-heading {
  margin: 0 0 14px;
  color: var(--color-text);
  font-size: 14px;
  font-weight: 800;
}

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

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

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

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

.footer-language-list a {
  display: inline-flex;
  min-height: 32px;
  align-items: center;
  padding: 4px 9px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  color: var(--color-muted);
  font-size: 12px;
}

.footer-language-list a[aria-current='true'] {
  border-color: var(--color-accent);
  color: var(--color-accent-dark);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  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: 18px;
}

.footer-legal a {
  min-height: 28px;
}

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

.prose > * {
  max-width: 100%;
}

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

.prose p {
  margin-bottom: 1.25em;
}

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

.prose h3 {
  margin-top: 1.7em;
}

.prose a:not(.btn) {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

.prose img {
  margin: 30px auto;
  border-radius: var(--radius-panel);
}

.prose table {
  border-collapse: collapse;
}

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

.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-radius: 50%;
  background: var(--color-text);
  color: var(--color-bg);
  content: counter(guide-step);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 800;
}

body:has(.toc-tabs) section[id] {
  scroll-margin-top: 136px;
}

@media (max-width: 1080px) {
  :root {
    --gutter: 24px;
    --section-space: 88px;
  }

  .desktop-nav {
    gap: 0;
    margin-left: 0;
  }

  .desktop-nav > a,
  .more-toggle {
    padding-inline: 11px;
  }

  .brand-local {
    display: none;
  }

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

@media (max-width: 900px) {
  .desktop-nav,
  .desktop-language {
    display: none;
  }

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

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

  .login-button {
    min-width: 66px;
    padding-inline: 17px;
  }
}

@media (max-width: 768px) {
  :root {
    --gutter: 20px;
    --section-space: 72px;
  }

  h1 {
    font-size: clamp(28px, 9vw, 40px);
    line-height: 1.12;
    letter-spacing: -0.018em;
  }

  h2 {
    font-size: clamp(28px, 7vw, 38px);
  }

  .lead {
    font-size: 18px;
  }

  .section-compact {
    padding-top: 52px;
    padding-bottom: 52px;
  }

  .footer-main {
    gap: 34px;
  }

  [data-parallax-decor] {
    transform: none;
  }
}

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

  body {
    overflow-x: clip;
  }

  .wrap,
  .shell,
  .reading-wrap {
    padding-inline: var(--gutter);
  }

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

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

  .button-row .btn {
    flex: 1 1 100%;
    width: 100%;
  }

  .header-inner {
    gap: 10px;
  }

  .brand {
    gap: 8px;
  }

  .brand-logo {
    width: 26px;
    height: 26px;
  }

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

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

  .login-button {
    min-width: 62px;
    min-height: 40px;
    padding-inline: 14px;
  }

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

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

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

  .card,
  .panel {
    padding: 20px;
  }
}

@media (max-width: 360px) {
  .brand-local {
    display: none;
  }

  .brand-name {
    font-size: 15px;
  }

  .login-button {
    min-width: 56px;
    padding-inline: 12px;
    font-size: 13px;
  }
}

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