:root {
  --bg: #FCFCFA;
  --bg-panel: #F5F4F0;
  --bg-panel-2: #ECEBE6;
  --border: #E2E1DB;
  --border-strong: #D3D1C9;
  --surface: #FFFFFF;
  --surface-bar: #FBFBF9;
  --surface-term: #FDFDFC;
  --accent: #0B5F7C;
  --accent-dark: #074359;
  --accent-tint: #E5EEF1;
  --on-accent: #FFFFFF;
  --text: #1C1B18;
  --text-muted: #64625C;
  --text-faint: #8E8B83;
  --success: #2F8F5B;
  --warn: #B7791F;
  --error: #C2412D;
  --field-a: #D9E4E7;
  --field-b: #ECE7DF;
  --field-c: #EAE4D9;
  --field-d: #DCE4E2;
  --field-glow: rgba(11,95,124,.07);
  --dot: rgba(28,27,24,.075);
  --hairline: rgba(28,27,24,.09);
  --veil: rgba(28,27,24,.25);
  --clear: transparent;
  --shadow-contact: 0 1px 0 rgba(28,27,24,.03), 0 1px 3px rgba(28,27,24,.06);
  --shadow-menu: 0 1px 2px rgba(28,27,24,.06), 0 8px 18px -12px rgba(28,27,24,.22);
  --r-ctl: 4px;
  --r-panel: 8px;
  --r-field: 6px;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-tab: 2px 2px 0 0;
  --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",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-strong: 600;
  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lg: 20px;
  --title-h1: clamp(34px,2.6vw + 12px,48px);
  --title-h2: clamp(24px,1.6vw + 12px,34px);
  --title-h3: 26px;
  --container: 1100px;
  --reading: 780px;
  --gutter: 40px;
  --header-height: 60px;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 72px;
  --space-9: 104px;
  --speed-fast: .15s;
  --speed-ui: .2s;
  --speed-reveal: .5s;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 84px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-normal);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--accent); text-underline-offset: .2em; }
img, svg { display: block; max-width: 100%; }
img { height: auto; }
svg, .icon, .eyebrow__dot { flex-shrink: 0; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
h1, h2, h3, h4, p, figure, pre { margin: 0; }
h1, h2, h3 { font-family: var(--font-display); font-weight: var(--weight-normal); text-wrap: balance; letter-spacing: -.02em; overflow-wrap: break-word; }
h1 { font-size: var(--title-h1); line-height: 1.16; }
h2 { font-size: var(--title-h2); line-height: 1.25; }
h3 { font-size: var(--title-h3); line-height: 1.3; }
strong { font-weight: var(--weight-medium); }
ul, ol { padding-left: 1.5em; }
button, a { -webkit-tap-highlight-color: var(--clear); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: var(--r-ctl); }
[hidden] { display: none !important; }
code { font-family: var(--font-mono); font-size: .875em; overflow-wrap: anywhere; }
pre { max-width: 100%; min-width: 0; overflow-x: auto; padding: 20px; border: 1px solid var(--border); border-radius: var(--r-panel); background: var(--surface-term); color: var(--text); }
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; font-size: var(--text-xs); }
.wrap { width: 100%; max-width: calc(var(--container) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.reading { max-width: calc(var(--reading) + var(--gutter) * 2); }
.section { padding-top: var(--space-8); padding-bottom: var(--space-8); }
.section__head { margin-bottom: var(--space-6); }
.section__head p { margin-top: 14px; color: var(--text-muted); }
.grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 24px; }
.grid > *, .wrap > *, .prose > *, .panel > *, .card > * { min-width: 0; }
.stack > * + * { margin-top: 20px; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-muted); }
.accent { color: var(--accent); }
.mono { font-family: var(--font-mono); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.panel, .card { min-width: 0; padding: 32px; border: 1px solid var(--border); border-radius: var(--r-panel); background: var(--bg-panel); color: var(--text); }
.panel--alternate { background: var(--bg-panel-2); color: var(--text); }
.card__mark { display: block; width: 8px; height: 8px; margin-bottom: 22px; background: var(--accent); }
.card p { margin-top: 12px; color: var(--text-muted); }
.card__link { display: inline-block; margin-top: 20px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 10px 20px; max-width: 100%;
  border: 1px solid var(--clear); border-radius: var(--r-ctl);
  font-size: 15px; font-weight: var(--weight-medium); line-height: 1.4;
  text-align: center; text-decoration: none;
  transition: background-color var(--speed-fast), border-color var(--speed-fast);
}
.btn svg { width: 16px; height: 16px; }
.btn--primary { background: var(--accent); color: var(--on-accent); }
.btn--primary:hover, .btn--primary.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn--ghost { background: var(--bg); color: var(--text); border-color: var(--text); }
.btn--ghost:hover, .btn--ghost.is-hover { background: var(--bg-panel); color: var(--text); }
.btn--primary:active { background: var(--accent-dark); color: var(--on-accent); }
.btn--ghost:active { background: var(--bg-panel-2); color: var(--text); }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--bg-panel-2); color: var(--text-muted); border-color: var(--border-strong); }
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 3px; }
.button-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

#site-header, .topbar { position: sticky; top: 0; z-index: 40; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); }
.topbar__inner {
  position: relative; width: 100%; max-width: min(100%,calc(1280px + var(--gutter) * 2));
  margin-inline: auto; padding-inline: var(--gutter); min-height: var(--header-height);
  display: flex; align-items: center; gap: 32px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; flex-shrink: 0; font-size: 17px; line-height: 1; letter-spacing: -.01em; color: var(--text); text-decoration: none; }
.brand__mark { width: 26px; height: 26px; flex-shrink: 0; }
.tabs { min-width: 0; height: var(--header-height); margin-left: auto; }
.tabs__list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; height: 100%; gap: 0; }
.tabs__list li { min-width: 0; height: 100%; }
.tabs__link { position: relative; display: flex; align-items: center; height: var(--header-height); padding-inline: 14px; color: var(--text-muted); text-decoration: none; font-size: 14.5px; white-space: nowrap; transition: color var(--speed-fast); }
.tabs__link::after { content: ""; position: absolute; left: 14px; right: 14px; bottom: -1px; height: 2px; border-radius: var(--r-tab); background: var(--accent); transform: scaleX(0); transition: transform var(--speed-ui); }
.tabs__link:hover, .tabs__link[aria-current="page"] { color: var(--text); }
.tabs__link[aria-current="page"]::after { transform: scaleX(1); }
.topbar__tools { display: flex; align-items: center; gap: 20px; flex-shrink: 0; }
.topbar__sep { height: 20px; width: 1px; background: var(--border); }
.language { position: relative; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 7px; min-height: 34px; padding: 7px 12px; border: 1px solid var(--border); border-radius: var(--r-ctl); background: var(--bg); color: var(--text-muted); font-size: var(--text-sm); line-height: 1; text-decoration: none; }
.lang svg { width: 15px; height: 15px; }
.lang:hover { border-color: var(--border-strong); color: var(--text); }
.lang__caret { font-size: 10px; }
.language__menu { position: absolute; top: calc(100% + 10px); right: 0; width: 180px; margin: 0; padding: 5px; list-style: none; border: 1px solid var(--border); border-radius: var(--r-panel); background: var(--surface); color: var(--text); box-shadow: var(--shadow-menu); }
.language__menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 12px; width: 100%; color: var(--text-muted); text-decoration: none; border-radius: var(--r-ctl); }
.language__menu a:hover, .language__menu a[aria-current="true"] { background: var(--bg-panel); color: var(--text); }
.hamburger { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--border); border-radius: var(--r-ctl); background: var(--bg); color: var(--text); }
.hamburger svg { width: 20px; height: 20px; }
.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 { padding-top: 56px; padding-bottom: 28px; background: var(--bg-panel); color: var(--text); border-top: 1px solid var(--border); }
.footer__grid { display: grid; grid-template-columns: 1.2fr .8fr 1.5fr; gap: 48px; }
.footer__grid > * { min-width: 0; }
.footer__intro { max-width: 320px; margin-top: 18px; font-size: var(--text-sm); color: var(--text-muted); }
.footer__title { margin-bottom: 16px; font-size: var(--text-sm); font-weight: var(--weight-medium); }
.footer__links { display: flex; flex-direction: column; list-style: none; margin: 0; padding: 0; gap: 8px; }
.footer__links a, .footer__languages a, .footer__legal a { color: var(--text-muted); text-decoration: none; font-size: var(--text-sm); }
.footer__links a:hover, .footer__languages a:hover, .footer__legal a:hover { color: var(--accent); text-decoration: underline; }
.footer__searches { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); }
.footer__languages { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 36px; }
.footer__languages a[aria-current="true"] { color: var(--text); text-decoration: underline; }
.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); color: var(--text-muted); font-size: var(--text-xs); }
.footer__legal { display: flex; flex-wrap: wrap; gap: 20px; }

.prose { min-width: 0; line-height: 1.85; }
.prose h2 { margin-top: 48px; margin-bottom: 20px; scroll-margin-top: 96px; }
.prose h3 { margin-top: 32px; margin-bottom: 14px; font-size: 23px; }
.prose p, .prose ul, .prose ol, .prose pre, .prose figure { margin-top: 16px; margin-bottom: 20px; }
.prose li + li { margin-top: 8px; }
.prose img { max-width: 100%; }
.prose code:not(pre code) { background: var(--bg-panel); color: var(--text); padding: 2px 4px; border-radius: var(--r-ctl); }
.hero, .decorated, [data-hero-visual] { overflow-x: clip; }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(14px); }
.reveal-ready .reveal { transition: opacity var(--speed-reveal) ease, transform var(--speed-reveal) ease; }
@media (max-width: 1100px) {
  .topbar__inner { gap: 16px; }
  .tabs__link { padding-inline: 10px; }
}
@media (max-width: 1000px) {
  :root { --gutter: 24px; }
}
@media (max-width: 860px) {
  .tabs--desktop { display: none; }
  .topbar__tools { margin-left: auto; gap: 10px; }
  .topbar__sep { display: none; }
  .hamburger { display: flex; }
  .mobile-nav:not([hidden]) { display: block; position: absolute; top: 100%; left: 0; right: 0; max-height: calc(100dvh - var(--header-height)); overflow-y: auto; overscroll-behavior: contain; padding: 12px var(--gutter) 24px; border-bottom: 1px solid var(--border); background: var(--bg); color: var(--text); }
  .mobile-nav ul { margin: 0; padding: 0; list-style: none; }
  .mobile-nav a { display: flex; align-items: center; min-height: 48px; width: 100%; padding: 12px 14px; color: var(--text-muted); text-decoration: none; border-radius: var(--r-ctl); }
  .mobile-nav a:hover, .mobile-nav a[aria-current] { background: var(--bg-panel); color: var(--text); }
  .mobile-nav__languages { margin-top: 12px !important; padding-top: 12px !important; border-top: 1px solid var(--border); }
  .footer__grid { gap: 32px; grid-template-columns: 1fr 1fr; }
  .footer__brand { grid-column: 1 / -1; }
}
@media (max-width: 768px) {
  :root { --title-h1: clamp(24px,4.1vw,30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .grid { grid-template-columns: minmax(0,1fr); }
  .brand { font-size: 15px; gap: 8px; }
  .lang { padding-inline: 8px; }
  .lang svg { display: none; }
  .topbar__inner { gap: 8px; }
  .topbar__tools { margin-left: auto; gap: 8px; }
  .panel, .card { padding: 24px; }
  .tilt, [data-tilt] { transform: none !important; }
  .footer__grid { grid-template-columns: minmax(0,1fr); }
  .footer__brand { grid-column: auto; }
  .footer__searches { gap: 10px; }
  .footer__languages { gap: 12px 18px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
  .reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}