:root {
  --bg: #FFFFFF;
  --bg-panel: #F7F8FA;
  --bg-panel-2: #EEF3FE;
  --border: #E3E7EF;
  --border-soft: #EEF0F5;
  --border-strong: #D3D9E4;
  --accent: #3B5BEF;
  --accent-2: #8E5CF0;
  --accent-dark: #2A43C4;
  --text: #121826;
  --text-soft: #3A4253;
  --text-muted: #5B6475;
  --text-faint: #8A93A3;
  --success: #1F9D6B;
  --success-soft: rgba(31,157,107,.14);
  --warn: #C98A12;
  --error: #D9443A;
  --on-accent: #FFFFFF;
  --skeleton: #E6E9F0;
  --skeleton-soft: #F0F2F6;
  --skeleton-strong: #D9DEE7;
  --clear: rgba(255,255,255,0);
  --glow-blue: rgba(59,91,239,.15);
  --glow-violet: rgba(142,92,240,.19);
  --halo: rgba(142,92,240,.07);
  --halo-line: rgba(142,92,240,.10);
  --halo-blue: rgba(59,91,239,.10);
  --halo-inner: rgba(110,92,240,.06);
  --wash: rgba(59,91,239,.05);
  --sheen: rgba(255,255,255,.22);
  --shadow-ink: rgba(18,24,38,.05);
  --shadow-ink-2: rgba(18,24,38,.10);
  --shadow-accent: rgba(42,67,196,.16);
  --shadow-accent-strong: rgba(42,67,196,.45);
  --veil: rgba(18,24,38,.28);

  --font-display: "Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Malgun Gothic","Microsoft YaHei",system-ui,sans-serif;
  --font-body: "Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Malgun Gothic","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono: "JetBrains Mono","SFMono-Regular",ui-monospace,Menlo,Consolas,"Liberation Mono",monospace;

  --r-panel: 32px;
  --r-window: 28px;
  --r-card: 20px;
  --r-bar: 20px;
  --r-btn: 14px;
  --r-field: 9px;
  --r-sm: 8px;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-skeleton: 4px;
  --r-line: 6px;
  --r-tool: 10px;

  --gutter: 24px;
  --content-width: 1120px;
  --reading-width: 800px;
  --header-width: 1280px;
  --section-space: 88px;
  --header-height: 74px;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-strong: 600;
  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lead: 20px;
  --title-display: clamp(34px,2.4vw + 12px,46px);
  --title-section: clamp(24px,1.6vw + 10px,34px);
  --title-card: 22px;
  --tracking-title: -.02em;
  --leading-body: 1.75;
  --grad-accent: linear-gradient(90deg,var(--accent) 0%,var(--accent-2) 100%);
  --shadow-card: 0 1px 2px var(--shadow-ink),0 14px 32px -24px var(--shadow-ink-2);
  --ease: cubic-bezier(.2,.65,.3,1);
  --duration: .2s;
}

*,*::before,*::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
[hidden] { display: none !important; }
img,svg,video { max-width: 100%; vertical-align: middle; }
img { height: auto; }
button,input,select,textarea { font: inherit; }
button,a,input,select,textarea,summary { -webkit-tap-highlight-color: var(--clear); }
button { cursor: pointer; }
a { color: inherit; text-underline-offset: .22em; }
a:hover { text-decoration-thickness: 2px; }
button:focus-visible,a:focus-visible,summary:focus-visible,[tabindex]:focus-visible,input:focus-visible {
  outline: 2px solid var(--accent-dark);
  outline-offset: 4px;
}
h1,h2,h3,h4,p,figure { margin-top: 0; }
h1,h2,h3 {
  font-family: var(--font-display);
  font-weight: var(--weight-normal);
  letter-spacing: var(--tracking-title);
  text-wrap: balance;
  overflow-wrap: normal;
}
h1 { font-size: var(--title-display); line-height: 1.1; }
h2 { font-size: var(--title-section); line-height: 1.25; }
h3 { font-size: var(--title-card); line-height: 1.4; }
strong { font-weight: var(--weight-strong); }
small { font-size: var(--text-sm); }
code,kbd,pre { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--r-btn);
  background: var(--bg-panel);
  color: var(--text-soft);
  font-size: var(--text-sm);
  line-height: 1.8;
  tab-size: 2;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
:target { scroll-margin-top: 100px; }
.wrap {
  width: 100%;
  max-width: calc(var(--content-width) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading-width) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.grid { display: grid; gap: 24px; grid-template-columns: repeat(2,minmax(0,1fr)); }
.grid > *, .flex > *, .footer-grid > *, .feat-head > * { min-width: 0; }
.flex { display: flex; gap: 16px; flex-wrap: wrap; align-items: center; }
.stack > * + * { margin-top: 24px; }
.muted { color: var(--text-muted); }
.nowrap { white-space: nowrap; }
.vh {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}
.grad {
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: var(--clear);
  color: var(--clear);
}
.prose { min-width: 0; }
.prose p { margin-bottom: 1.3em; }
.prose h2 { margin-top: 2.5em; margin-bottom: .8em; }
.prose h3 { margin-top: 1.8em; margin-bottom: .7em; }
.prose li + li { margin-top: .5em; }
.prose ul,.prose ol { padding-left: 1.5em; }
.prose :not(pre) > code {
  background: var(--bg-panel);
  color: var(--text-soft);
  border-radius: var(--r-skeleton);
  padding: .12em .32em;
  font-size: .9em;
}
.btn {
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid var(--clear);
  border-radius: var(--r-btn);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 15px;
  font-weight: var(--weight-medium);
  line-height: 1.4;
  text-decoration: none;
  white-space: normal;
  text-align: center;
  transition: transform var(--duration) var(--ease),box-shadow var(--duration) var(--ease),background-color var(--duration) var(--ease),border-color var(--duration) var(--ease);
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn--primary {
  background: var(--accent);
  color: var(--on-accent);
  box-shadow: inset 0 1px 0 var(--sheen),0 1px 2px var(--shadow-accent),0 10px 22px -10px var(--shadow-accent-strong);
}
.btn--primary:hover,.btn--primary.is-hover { background: var(--accent-dark); color: var(--on-accent); transform: translateY(-1px); }
.btn--ghost {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border-strong);
  box-shadow: 0 1px 2px var(--shadow-ink);
}
.btn--ghost:hover,.btn--ghost.is-hover { border-color: var(--text-faint); transform: translateY(-1px); }
.btn--ghost svg { color: var(--text-muted); }
.btn--pill {
  min-height: 44px;
  padding-inline: 20px;
  border-radius: var(--r-pill);
  border-color: var(--border-strong);
  background: var(--bg);
  color: var(--text);
}
.btn--pill:hover { border-color: var(--text-muted); }
.btn:active { transform: translateY(1px); }
.btn.is-focus { outline: 2px solid var(--accent-dark); outline-offset: 4px; }
.btn:disabled,.btn[aria-disabled="true"] {
  background: var(--bg-panel);
  color: var(--text-muted);
  border-color: var(--border);
  box-shadow: none;
  transform: none;
  cursor: not-allowed;
}
.card {
  min-width: 0;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-card);
}
.card p:last-child { margin-bottom: 0; }
.panel {
  margin-inline: 16px;
  padding: 72px var(--gutter) 88px;
  background: var(--bg-panel-2);
  color: var(--text);
  border-radius: var(--r-panel);
  overflow-x: clip;
}
.panel__inner { max-width: var(--content-width); margin-inline: auto; min-width: 0; }
.decorated,.hero,[data-hero-visual] { overflow-x: clip; }

.topbar { padding: 14px 16px 0; position: relative; z-index: 40; }
.topbar__bar {
  max-width: 1408px;
  height: 60px;
  margin-inline: auto;
  padding-inline: 24px;
  background: var(--bg-panel);
  color: var(--text);
  border-radius: var(--r-bar);
}
.topbar__inner {
  max-width: min(100%,calc(var(--header-width) + var(--gutter) * 2));
  height: 100%;
  margin-inline: auto;
  display: flex;
  align-items: center;
  position: relative;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
  font-size: 16px;
  font-weight: var(--weight-medium);
  letter-spacing: -.01em;
  color: var(--text);
}
.brand img { display: block; width: 30px; height: 30px; flex-shrink: 0; }
.mainnav { margin-left: auto; min-width: 0; }
.mainnav ul {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: clamp(16px,2.35vw,34px);
}
.mainnav li { min-width: 0; }
.mainnav a {
  display: block;
  padding-block: 10px;
  color: var(--text-muted);
  font-size: 14.5px;
  text-decoration: none;
  letter-spacing: .005em;
  white-space: nowrap;
}
.mainnav a:hover { color: var(--text); }
.mainnav a[aria-current="page"] { color: var(--text); font-weight: var(--weight-medium); }
.header-tools { display: flex; align-items: center; flex-shrink: 0; margin-left: 34px; }
.language { position: relative; }
.lang {
  min-height: 44px;
  padding: 4px 0 4px 22px;
  border: 0;
  background: var(--clear);
  color: var(--text-muted);
  font-size: 14px;
  white-space: nowrap;
}
.lang::before { content: ""; position: absolute; left: 0; top: 14px; bottom: 14px; border-left: 1px solid var(--border-strong); }
.lang-short { display: none; }
.language-menu {
  position: absolute;
  z-index: 4;
  right: 0;
  top: calc(100% + 10px);
  min-width: 180px;
  margin: 0;
  padding: 8px;
  list-style: none;
  border: 1px solid var(--border);
  border-radius: var(--r-btn);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-card);
}
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 8px 12px; text-decoration: none; border-radius: var(--r-sm); }
.language-menu a:hover,.language-menu a[aria-current="true"] { background: var(--bg-panel); color: var(--text); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  margin-left: 6px;
  padding: 10px;
  border: 0;
  border-radius: var(--r-sm);
  background: var(--clear);
  color: var(--text);
}
.menu-toggle svg { width: 22px; height: 22px; flex-shrink: 0; }
.mobile-nav { display: none; }
.nav-veil {
  position: fixed;
  inset: var(--header-height) 0 0;
  z-index: 30;
  border: 0;
  background: var(--veil);
  color: var(--text);
}
.site-footer {
  margin-top: 88px;
  padding-top: 64px;
  padding-bottom: 28px;
  border-top: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
}
.footer-grid { display: grid; grid-template-columns: 1.2fr .8fr 1.2fr; gap: 48px; }
.footer-brand p { max-width: 340px; margin-top: 18px; color: var(--text-muted); font-size: var(--text-sm); }
.footer-title { font-size: var(--text-sm); font-weight: var(--weight-medium); margin-bottom: 16px; }
.footer-links { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.footer-links a { display: inline-block; color: var(--text-muted); font-size: var(--text-sm); text-decoration: none; padding-block: 3px; }
.footer-links a:hover { color: var(--text); text-decoration: underline; }
.footer-languages { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 40px; }
.footer-languages a { font-size: var(--text-sm); color: var(--text-muted); padding-block: 8px; }
.footer-bottom { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 16px; margin-top: 24px; padding-top: 24px; border-top: 1px solid var(--border); font-size: var(--text-xs); color: var(--text-muted); }
.footer-bottom p { margin: 0; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 16px; }
.footer-legal a { padding-block: 6px; }

.reveal { opacity: 1; transform: none; }
html.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
html.reveal-ready .reveal { transition: opacity .55s var(--ease),transform .55s var(--ease); }
.reveal.shown { opacity: 1; transform: none; }

@media (max-width: 1100px) {
  .header-tools { margin-left: 20px; }
  .mainnav ul { gap: 18px; }
}
@media (max-width: 960px) {
  .mainnav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
  .lang { padding-left: 0; }
  .lang::before { display: none; }
  .mobile-nav:not([hidden]) {
    display: block;
    position: absolute;
    top: calc(100% + 14px);
    left: -8px;
    right: -8px;
    padding: 16px;
    max-height: calc(100dvh - 92px);
    overflow-y: auto;
    overscroll-behavior: contain;
    background: var(--bg);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--r-card);
    box-shadow: var(--shadow-card);
  }
  .mobile-nav ul { list-style: none; margin: 0; padding: 0; }
  .mobile-nav a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 10px 16px; text-decoration: none; border-radius: var(--r-sm); }
  .mobile-nav a:hover,.mobile-nav a[aria-current] { background: var(--bg-panel); color: var(--text); }
  .mobile-nav__languages { border-top: 1px solid var(--border); margin-top: 12px !important; padding-top: 12px !important; }
  .footer-grid { gap: 32px; grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 768px) {
  :root { --title-display: clamp(24px,4vw,30px); --section-space: 56px; }
  .grid { grid-template-columns: minmax(0,1fr); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .wrap { width: 100%; padding-inline: var(--gutter); }
  .topbar { padding-inline: 12px; }
  .topbar__bar { padding-inline: 12px; }
  .brand { font-size: 14px; gap: 8px; }
  .brand img { width: 28px; height: 28px; }
  .lang-long { display: none; }
  .lang-short { display: inline; }
  .lang { min-width: 44px; }
  .header-tools { margin-left: auto; }
  .card { padding: 22px; }
  .panel { margin-inline: 12px; padding-inline: var(--gutter); padding-top: 48px; padding-bottom: 56px; }
  .footer-grid { grid-template-columns: minmax(0,1fr); }
  .footer-brand { grid-column: auto; }
  .site-footer { margin-top: 56px; padding-top: 40px; }
  .tilt,[data-tilt] { transform: none !important; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,*::before,*::after { transition: none !important; animation: none !important; }
  html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}
@media print {
  .header-tools,.mobile-nav,.nav-veil { display: none !important; }
  html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}