:root {
  --color-bg: #14231B;
  --color-panel: #1B2E24;
  --color-panel-raised: #233A2E;
  --color-border: #3A5546;
  --color-ring: #4A6553;
  --color-ring-soft: #33493C;
  --color-accent: #E88FA7;
  --color-accent-dark: #C9647F;
  --color-text: #F2EDE3;
  --color-muted: #A9B8A8;
  --color-success: #7FC98F;
  --color-warn: #E0B45C;
  --color-error: #E06A5A;
  --color-focus: #E88FA7;
  --color-shadow: rgba(5, 15, 9, .42);
  --color-hairline: rgba(58, 85, 70, .55);
  --color-accent-glow: rgba(232, 143, 167, .16);
  --color-accent-glow-strong: rgba(232, 143, 167, .28);
  --color-green-glow: rgba(35, 58, 46, .9);
  --color-panel-translucent: rgba(27, 46, 36, .86);
  --color-noise: rgba(242, 237, 227, .05);
  --flag-white: #F2EDE3;
  --flag-red: #C4394A;
  --flag-blue: #2E4B85;
  --flag-gold: #E0B45C;
  --flag-black: #1E1F1C;
  --font-display: Georgia, "Times New Roman", "Songti SC", "SimSun", "Noto Sans SC", serif;
  --font-body: "Inter", "Noto Sans SC", -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 30px;
  --radius-pill: 999px;
  --header-height: 76px;
  --content-width: 1320px;
  --reading-width: 820px;
  --gutter: clamp(16px, 4vw, 48px);
  --section-space: clamp(72px, 9vw, 132px);
  --shadow-panel: 0 24px 70px var(--color-shadow);
  --transition-fast: 180ms ease;
  --transition-reveal: 680ms cubic-bezier(.2, .7, .2, 1);
  --toc-offset: 94px;
}

*,
*::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:
    radial-gradient(circle at 12% 12%, var(--color-green-glow), transparent 34rem),
    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;
}

body::before {
  position: fixed;
  z-index: -1;
  inset: 0;
  background-image:
    linear-gradient(var(--color-noise) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-noise) 1px, transparent 1px);
  background-size: 38px 38px;
  mask-image: linear-gradient(to bottom, transparent, var(--color-bg), transparent);
  content: "";
  pointer-events: none;
  opacity: .22;
}

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

img {
  height: auto;
}

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

button {
  border: 0;
  cursor: pointer;
}

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

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

h1,
h2,
h3,
h4 {
  color: var(--color-text);
  font-family: var(--font-display);
  font-weight: 400;
  text-wrap: balance;
}

h1 {
  margin-bottom: 24px;
  font-size: clamp(52px, 5vw, 72px);
  line-height: 1.12;
  letter-spacing: .005em;
}

h2 {
  margin-bottom: 24px;
  font-size: clamp(36px, 4vw, 54px);
  line-height: 1.16;
}

h3 {
  margin-bottom: 14px;
  font-size: clamp(24px, 2.4vw, 32px);
  line-height: 1.25;
}

p {
  margin-bottom: 1.15em;
}

strong {
  color: var(--color-text);
  font-weight: 650;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

.section-head {
  max-width: 760px;
  margin-bottom: clamp(34px, 5vw, 64px);
}

.eyebrow,
.badge {
  display: inline-flex;
  min-height: 30px;
  max-width: 100%;
  align-items: center;
  gap: 9px;
  overflow: hidden;
  padding: 5px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  background: var(--color-panel);
  color: var(--color-muted);
  font-size: 13px;
  letter-spacing: .06em;
}

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

.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: var(--radius-pill);
  background: var(--color-success);
  box-shadow: 0 0 12px var(--color-success);
}

.btn {
  display: inline-flex;
  min-width: 24px;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 30px;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  font-weight: 600;
  letter-spacing: .03em;
  line-height: 1.2;
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast),
    background-color var(--transition-fast),
    color var(--transition-fast),
    box-shadow var(--transition-fast);
}

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

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
  box-shadow: 0 8px 30px var(--color-accent-glow);
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  box-shadow: 0 12px 36px var(--color-accent-glow-strong);
}

.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);
}

.btn-small {
  min-height: 40px;
  padding: 9px 18px;
  font-size: 14px;
}

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

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

.panel {
  padding: clamp(24px, 4vw, 44px);
}

.card {
  position: relative;
  padding: clamp(22px, 3vw, 32px);
  box-shadow: 0 16px 50px var(--color-shadow);
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
  transform-style: preserve-3d;
}

.card:hover {
  border-color: var(--color-ring);
  box-shadow: var(--shadow-panel);
}

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

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.card-grid > * {
  min-width: 0;
}

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

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

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

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

.header-shell {
  display: flex;
  width: 100%;
  height: 100%;
  align-items: center;
  gap: 30px;
  padding-inline: var(--gutter);
}

.brand-link {
  display: inline-flex;
  min-width: max-content;
  min-height: 44px;
  align-items: center;
  gap: 11px;
}

.brand-logo {
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 21px;
  letter-spacing: .04em;
}

.brand-local {
  color: var(--color-muted);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 400;
}

.desktop-nav {
  display: flex;
  min-width: 0;
  flex: 1 1 auto;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
}

.desktop-nav a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: var(--color-muted);
  font-size: 14px;
  transition: color var(--transition-fast);
}

.desktop-nav a:not(:first-child)::before {
  padding-inline: 12px;
  color: var(--color-muted);
  content: "·";
  opacity: .55;
}

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

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

.header-tools {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 12px;
}

.language-picker {
  position: relative;
}

.language-trigger {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  gap: 7px;
  padding-inline: 8px;
  background: transparent;
  color: var(--color-muted);
  font-size: 13px;
}

.language-menu {
  position: absolute;
  z-index: 64;
  top: calc(100% + 8px);
  right: 0;
  display: none;
  width: 170px;
  overflow: hidden;
  padding: 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-panel-raised);
  box-shadow: var(--shadow-panel);
}

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

.language-menu a {
  display: flex;
  min-height: 44px;
  align-items: center;
  padding-inline: 12px;
  border-radius: var(--radius-sm);
  color: var(--color-muted);
}

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

.header-login {
  min-height: 40px;
  padding: 9px 22px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-text);
  font-size: 14px;
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast);
}

.header-login:hover {
  border-color: var(--color-accent);
  transform: translateY(-1px);
}

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

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

.mobile-nav {
  position: absolute;
  z-index: 63;
  top: var(--header-height);
  right: 0;
  left: 0;
  display: none;
  max-height: calc(100dvh - var(--header-height));
  overflow-y: auto;
  padding: 10px var(--gutter) 20px;
  border-bottom: 1px solid var(--color-border);
  background: var(--color-panel-raised);
  overscroll-behavior: contain;
}

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

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

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

.mobile-language-label {
  padding-top: 14px;
  color: var(--color-muted);
  font-size: 12px;
  letter-spacing: .1em;
}

.mobile-language-list {
  display: grid;
  grid-template-columns: 1fr;
}

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

.nav-veil {
  position: fixed;
  z-index: 40;
  inset: var(--header-height) 0 0;
  display: none;
  background: var(--color-shadow);
}

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

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

.footer-main {
  display: grid;
  grid-template-columns: minmax(240px, 1.3fr) repeat(3, minmax(150px, 1fr));
  gap: 40px;
  padding-top: 64px;
  padding-bottom: 52px;
}

.footer-brand p {
  max-width: 400px;
  margin-top: 20px;
  color: var(--color-muted);
}

.footer-heading {
  margin-bottom: 16px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 650;
  letter-spacing: .08em;
}

.footer-links {
  display: grid;
  gap: 7px;
}

.footer-links a {
  display: inline-flex;
  width: fit-content;
  min-height: 30px;
  align-items: center;
  color: var(--color-muted);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 22px;
  padding-bottom: 24px;
  border-top: 1px solid var(--color-hairline);
  color: var(--color-muted);
  font-size: 13px;
}

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

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

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

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

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

.prose a.btn.btn-primary {
  color: var(--color-bg);
  text-decoration: none;
}

.prose li + li {
  margin-top: 8px;
}

@media (max-width: 1120px) {
  .desktop-nav a:not(:first-child)::before {
    padding-inline: 8px;
  }

  .desktop-nav a {
    font-size: 13px;
  }

  .header-shell {
    gap: 18px;
  }
}

@media (max-width: 940px) {
  .desktop-nav,
  .language-picker {
    display: none;
  }

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

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

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

@media (max-width: 768px) {
  h1 {
    font-size: clamp(32px, 9.5vw, 40px);
    line-height: 1.14;
  }

  h2 {
    font-size: clamp(30px, 8vw, 40px);
  }

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

  .header-shell {
    padding-inline: var(--gutter);
  }

  .brand-local {
    display: none;
  }
}

@media (max-width: 640px) {
  :root {
    --gutter: 16px;
    --header-height: 68px;
  }

  body,
  main,
  section,
  article,
  .wrap,
  .reading-wrap,
  .panel,
  .card {
    min-width: 0;
  }

  .tilt,
  [data-tilt],
  .decorative-tilt {
    transform: none;
  }

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

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

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

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

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

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

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