:root {
  --color-page: #FFFFFF;
  --color-panel: #F6F7F9;
  --color-panel-strong: #EEF1F5;
  --color-deep: #0B1220;
  --color-deep-raised: #182234;
  --color-deep-line: #2C3850;
  --color-screen: #0D1526;
  --color-border: #E4E7EC;
  --color-accent: #FF4A26;
  --color-accent-end: #E0186F;
  --color-accent-dark: #D6215C;
  --color-cyan: #12C4DE;
  --color-text: #101625;
  --color-text-muted: #5A6272;
  --color-success: #12A97C;
  --color-warning: #F59E0B;
  --color-error: #DC2626;
  --color-white: #FFFFFF;
  --color-hero-text: #FFFFFF;
  --color-hero-muted: #A9B2C5;
  --color-hero-faint: #7C8699;
  --color-wall: #39435A;
  --color-wall-line: #2D3648;
  --color-wall-cap: #4B5872;
  --color-flag-red: #C93C32;
  --color-flag-blue: #2B4B9B;
  --color-flag-white: #F5F7FA;
  --color-flag-gold: #E8B62E;
  --color-flag-black: #20242C;
  --color-transparent: transparent;
  --color-overlay: rgba(11, 18, 32, 0.62);
  --color-shadow: rgba(16, 22, 37, 0.12);
  --color-shadow-strong: rgba(16, 22, 37, 0.2);
  --color-hero-line: rgba(255, 255, 255, 0.13);
  --color-hero-chip: rgba(255, 255, 255, 0.05);
  --color-hero-border-hover: rgba(255, 255, 255, 0.5);
  --color-accent-shadow: rgba(224, 24, 111, 0.36);
  --color-accent-shadow-strong: rgba(224, 24, 111, 0.4);
  --color-cyan-glow: rgba(18, 196, 222, 0.1);
  --color-pink-glow: rgba(224, 24, 111, 0.12);
  --color-cyan-tint: rgba(18, 196, 222, 0.08);
  --color-accent-tint: rgba(255, 74, 38, 0.08);
  --color-success-tint: rgba(18, 169, 124, 0.1);
  --color-warning-tint: rgba(245, 158, 11, 0.12);
  --color-error-tint: rgba(220, 38, 38, 0.1);

  --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: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-card: 26px;
  --radius-pill: 999px;

  --shadow-card: 0 12px 32px var(--color-shadow);
  --shadow-float: 0 10px 28px var(--color-accent-shadow-strong);
  --shadow-focus: 0 0 0 3px var(--color-cyan-tint);

  --page-max: 1408px;
  --content-max: 1120px;
  --prose-max: 800px;
  --gutter: clamp(16px, 3vw, 28px);
  --header-height: 64px;
  --toc-top: 72px;
  --toc-height: 54px;
  --section-space: clamp(56px, 8vw, 104px);
  --transition-fast: 160ms ease;
  --transition-base: 260ms ease;
  --transition-reveal: 560ms cubic-bezier(0.2, 0.72, 0.25, 1);
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

html.nav-open {
  overflow: hidden;
}

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

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

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

img {
  height: auto;
}

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

button,
select {
  color: inherit;
}

button,
summary {
  cursor: pointer;
}

button {
  border: 0;
}

ul,
ol {
  padding-left: 1.25em;
}

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

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

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5vw, 72px);
  font-weight: 900;
  letter-spacing: -0.015em;
  line-height: 1.1;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(30px, 3.4vw, 46px);
  font-weight: 850;
  letter-spacing: -0.012em;
  line-height: 1.18;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 760;
  line-height: 1.3;
}

p {
  margin-bottom: 1em;
}

strong {
  font-weight: 700;
}

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

code {
  overflow-wrap: anywhere;
}

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

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

table {
  border-collapse: collapse;
}

:focus-visible {
  outline: 2px solid var(--color-cyan);
  outline-offset: 3px;
}

::selection {
  background: var(--color-cyan);
  color: var(--color-deep);
}

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

.wrap,
.wrap-wide,
.prose-wrap {
  width: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap {
  max-width: var(--content-max);
}

.wrap-wide {
  max-width: var(--page-max);
}

.prose-wrap {
  max-width: calc(var(--prose-max) + var(--gutter) + var(--gutter));
}

.section {
  padding-top: var(--section-space);
  padding-bottom: var(--section-space);
}

.section-compact {
  padding-top: clamp(36px, 5vw, 64px);
  padding-bottom: clamp(36px, 5vw, 64px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-heading p {
  color: var(--color-text-muted);
  font-size: 17px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  max-width: 100%;
  margin-bottom: 14px;
  padding: 5px 11px;
  overflow: hidden;
  border: 1px solid var(--color-cyan);
  border-radius: var(--radius-xs);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.badge,
.tag,
.fact-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  max-width: 100%;
  overflow: hidden;
  border-radius: var(--radius-pill);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.badge,
.tag {
  padding: 5px 10px;
  border: 1px solid var(--color-border);
  background: var(--color-page);
  color: var(--color-text-muted);
  font-size: 12px;
  font-weight: 650;
}

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

.badge--cyan {
  border-color: var(--color-cyan);
  background: var(--color-cyan-tint);
  color: var(--color-text);
}

.status-dot,
.badge-dot,
.icon-dot {
  width: 7px;
  height: 7px;
  flex-shrink: 0;
  border-radius: 50%;
  background: var(--color-success);
}

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

.panel {
  padding: clamp(20px, 3vw, 32px);
}

.card {
  padding: 24px;
  transition: border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.card:hover {
  border-color: var(--color-text-muted);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

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

.panel-deep {
  border-color: var(--color-deep-line);
  background: var(--color-deep);
  color: var(--color-hero-muted);
}

.panel-deep h2,
.panel-deep h3 {
  color: var(--color-hero-text);
}

.btn {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: var(--color-page);
  color: var(--color-text);
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  transition: filter var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
}

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

.btn-primary {
  border-color: var(--color-transparent);
  background: linear-gradient(94deg, var(--color-accent), var(--color-accent-end));
  color: var(--color-white);
  box-shadow: 0 8px 26px var(--color-accent-shadow);
}

.btn-primary:hover {
  border-color: var(--color-transparent);
  background: linear-gradient(94deg, var(--color-accent), var(--color-accent-end));
  filter: brightness(1.07);
}

.btn-dark {
  border-color: var(--color-deep);
  background: var(--color-deep);
  color: var(--color-white);
}

.btn-ghost-dark {
  border-color: var(--color-hero-line);
  background: var(--color-transparent);
  color: var(--color-hero-text);
}

.btn-ghost-dark:hover {
  border-color: var(--color-hero-border-hover);
  background: var(--color-hero-chip);
}

.btn-sm {
  min-height: 38px;
  padding: 8px 15px;
  font-size: 13px;
}

.btn:disabled,
.btn.is-disabled {
  cursor: not-allowed;
  filter: grayscale(1);
  opacity: 0.5;
  transform: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

.header-in {
  display: flex;
  width: 100%;
  max-width: var(--page-max);
  height: var(--header-height);
  align-items: center;
  gap: 24px;
  margin-inline: auto;
  padding-inline: 16px;
}

.brand {
  display: inline-flex;
  min-width: 0;
  flex-shrink: 0;
  align-items: center;
  gap: 9px;
}

.brand-mark {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.brand-copy {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  white-space: nowrap;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 850;
  letter-spacing: 0.02em;
}

.brand-local {
  color: var(--color-text-muted);
  font-size: 12px;
  font-weight: 560;
}

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

.main-nav a {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  gap: 6px;
  padding: 7px 9px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 550;
  white-space: nowrap;
}

.main-nav a svg {
  width: 15px;
  height: 15px;
  flex-shrink: 0;
}

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

.main-nav a.is-active {
  font-weight: 700;
}

.main-nav a.is-active svg {
  color: var(--color-accent);
}

.header-tools {
  display: flex;
  flex-shrink: 0;
  align-items: center;
  gap: 9px;
}

.language-menu {
  position: relative;
}

.language-trigger {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  gap: 5px;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  background: var(--color-page);
  color: var(--color-text-muted);
  font-size: 12px;
}

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

.language-popover {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  display: none;
  width: 166px;
  padding: 6px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-page);
  box-shadow: var(--shadow-card);
}

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

.language-popover a {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 13px;
}

.language-popover a:hover,
.language-popover 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 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-page);
  color: var(--color-text);
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}

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

.menu-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: var(--color-page);
}

.menu-toggle svg {
  width: 22px;
  height: 22px;
}

.mobile-nav {
  position: absolute;
  top: var(--header-height);
  right: 0;
  left: 0;
  z-index: 102;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 10px var(--gutter) 18px;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-page);
  box-shadow: var(--shadow-card);
}

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

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

.mobile-nav a svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

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

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

.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-grid {
  display: grid;
  grid-template-columns: minmax(220px, 1.4fr) repeat(3, minmax(150px, 1fr));
  gap: 34px;
  padding-top: 54px;
  padding-bottom: 42px;
}

.footer-brand p {
  max-width: 330px;
  margin-top: 16px;
  color: var(--color-text-muted);
}

.footer-heading {
  margin-bottom: 14px;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.footer-links {
  display: grid;
  gap: 8px;
  padding: 0;
  list-style: none;
}

.footer-links a {
  color: var(--color-text-muted);
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--color-text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding-top: 18px;
  padding-bottom: 24px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 12px;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

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

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

.prose h2,
.prose h3 {
  scroll-margin-top: calc(var(--toc-top) + var(--toc-height) + 18px);
}

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

.prose a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.prose table {
  width: 100%;
}

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

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

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

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

@media (max-width: 1180px) {
  .main-nav a {
    padding-inline: 6px;
    font-size: 12px;
  }

  .brand-local {
    display: none;
  }
}

@media (max-width: 980px) {
  .main-nav,
  .language-menu {
    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) {
  h1 {
    font-size: clamp(32px, 9vw, 40px);
    line-height: 1.12;
    letter-spacing: -0.012em;
  }

  h2 {
    font-size: clamp(27px, 7vw, 36px);
  }

  .header-in {
    gap: 10px;
  }

  .brand-copy {
    gap: 0;
  }

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

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

  .decorative-label,
  .absolute-caption {
    display: none;
  }
}

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

  body {
    font-size: 14px;
  }

  .wrap,
  .wrap-wide,
  .prose-wrap {
    padding-inline: var(--gutter);
  }

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

  .card,
  .panel {
    padding: 18px;
  }

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

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

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

@media (max-width: 390px) {
  .brand-name {
    font-size: 15px;
  }

  .brand-local {
    display: none;
  }

  .header-login {
    padding-inline: 10px;
  }
}

@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;
  }
}