:root {
  --bg: #FFFFFF;
  --bg-panel: #F6F8F9;
  --bg-panel-2: #EDF1F3;
  --border: #E1E6EA;
  --border-soft: #EAEEF1;
  --line-faint: #EEF1F3;
  --dot: #D4DADF;
  --accent: #0891A8;
  --accent-2: #13B58C;
  --accent-dark: #066B7D;
  --accent-tint: #E9F6F4;
  --accent-tint-line: #CBEAE5;
  --on-accent: #FFFFFF;
  --text: #14181C;
  --text-muted: #5E6872;
  --text-faint: #8F99A2;
  --success: #1E9E5A;
  --warn: #C98A0B;
  --error: #D6453D;
  --clear: transparent;
  --glow: rgba(8, 145, 168, 0.07);
  --glow-2: rgba(19, 181, 140, 0.06);
  --veil: rgba(20, 24, 28, 0.24);
  --texture: rgba(255, 255, 255, 0.18);
  --grad: linear-gradient(90deg, #0891A8 0%, #13B58C 100%);
  --shadow-xs: 0 1px 2px rgba(20, 24, 28, 0.04);
  --shadow-card: 0 1px 2px rgba(20, 24, 28, 0.05), 0 12px 32px rgba(20, 24, 28, 0.05);
  --shadow-window: 0 1px 2px rgba(20, 24, 28, 0.05), 0 12px 32px rgba(20, 24, 28, 0.05), 0 32px 72px rgba(8, 107, 125, 0.06);
  --shadow-cta: 0 1px 2px rgba(6, 107, 125, 0.18), 0 8px 22px rgba(8, 145, 168, 0.22);
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius: 8px;
  --radius-round: 50%;
  --radius-bubble: 8px 8px 8px 2px;
  --font-display: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SFMono-Regular', Menlo, Consolas, monospace;
  --gutter: 32px;
  --content-width: 1100px;
  --reading-width: 800px;
  --header-width: 1280px;
  --header-height: 64px;
  --size-h1: clamp(34px, 3.4vw, 48px);
  --size-h2: 30px;
  --size-h3: 21px;
  --size-body: 15px;
  --weight-regular: 400;
  --weight-medium: 500;
  --weight-strong: 600;
  --tracking-display: -0.02em;
  --tracking-brand: -0.01em;
  --tracking-label: 0.02em;
  --line-body: 1.6;
  --section-space: 88px;
  --motion-fast: 160ms;
  --motion-reveal: 540ms;
  --feature-duration: 9s;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 88px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--size-body);
  line-height: var(--line-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
::selection { background: var(--accent-tint); color: var(--text); }
[hidden] { display: none !important; }
a { color: inherit; text-underline-offset: 0.2em; }
button, input, select, textarea { font: inherit; }
button, summary { cursor: pointer; }
button { color: inherit; }
img { display: block; max-width: 100%; height: auto; }
svg { display: block; flex-shrink: 0; }
figure { margin: 0; }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: var(--weight-regular); text-wrap: balance; }
h1 { margin: 0 0 20px; font-size: var(--size-h1); line-height: 1.16; letter-spacing: var(--tracking-display); }
h2 { margin: 0 0 18px; font-size: var(--size-h2); line-height: 1.3; letter-spacing: var(--tracking-brand); }
h3 { margin: 0 0 12px; font-size: var(--size-h3); line-height: 1.4; }
p { margin: 0 0 18px; }
strong { font-weight: var(--weight-strong); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre { max-width: 100%; overflow-x: auto; white-space: pre; }
pre code { overflow-wrap: normal; word-break: normal; }
a:focus-visible, button:focus-visible, summary:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--accent-dark);
  outline-offset: 3px;
}
.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); }
.section-panel { background: var(--bg-panel); color: var(--text); }
.decorated { position: relative; overflow-x: clip; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-muted); }
.mono { font-family: var(--font-mono); }
.eyebrow { margin: 0 0 10px; color: var(--accent-dark); font-family: var(--font-mono); font-size: 12px; }
.section-head { margin-bottom: 40px; }
.section-head.center { text-align: center; }
.section-head p { margin: 0; color: var(--text-muted); }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.grid > *, .split > *, .wrap > *, .card > * { min-width: 0; }
.split { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.card, .panel {
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-card);
}
.panel { box-shadow: var(--shadow-xs); }
.card p:last-child, .panel p:last-child { margin-bottom: 0; }
.button-row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  max-width: 100%;
  padding: 10px 22px;
  border: 1px solid var(--clear);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 15.5px;
  font-weight: var(--weight-medium);
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--motion-fast), box-shadow var(--motion-fast), border-color var(--motion-fast), background-color var(--motion-fast);
}
.btn svg { width: 17px; height: 17px; }
.btn-primary { background: var(--grad); color: var(--on-accent); box-shadow: var(--shadow-cta); }
.btn-primary:hover, .btn-primary.demo-hover { transform: translateY(-1px); }
.btn-ghost { background: var(--bg); color: var(--accent-dark); border-color: var(--border); box-shadow: var(--shadow-xs); }
.btn-ghost:hover, .btn-ghost.demo-hover { background: var(--accent-tint); color: var(--accent-dark); border-color: var(--accent-tint-line); }
.btn:active, .btn.demo-active { transform: translateY(1px); box-shadow: var(--shadow-xs); }
.btn:disabled, .btn[aria-disabled="true"] { background: var(--bg-panel-2); color: var(--text-muted); border-color: var(--border); box-shadow: none; cursor: not-allowed; transform: none; }
.btn.demo-focus { outline: 2px solid var(--accent-dark); outline-offset: 3px; }
.btn-small { min-height: 40px; padding: 8px 14px; font-size: 14px; }
.icon { width: 20px; height: 20px; flex-shrink: 0; }
.icon-defs { position: absolute; width: 0; height: 0; overflow: hidden; }
.skip-link { position: fixed; top: -100px; left: var(--gutter); z-index: 100; padding: 12px 18px; background: var(--bg); color: var(--text); border: 1px solid var(--border); border-radius: var(--radius); }
.skip-link:focus { top: 8px; }
#site-header, .topbar { position: sticky; top: 0; z-index: 40; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border-soft); }
.topbar-inner {
  position: relative;
  max-width: min(100%, calc(var(--header-width) + var(--gutter) * 2));
  min-height: var(--header-height);
  margin: 0 auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 20px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; margin-right: auto; flex-shrink: 0; text-decoration: none; color: var(--text); font-family: var(--font-display); font-size: 17px; font-weight: var(--weight-strong); letter-spacing: var(--tracking-brand); }
.brand-mark { width: 28px; height: 28px; flex-shrink: 0; }
.mainnav { min-width: 0; }
.mainnav-list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 2px; }
.mainnav-link, .more-btn {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 44px;
  padding: 8px 13px;
  border: 0;
  border-radius: var(--radius-sm);
  background: var(--clear);
  color: var(--text-muted);
  font: inherit;
  font-size: 14.5px;
  text-decoration: none;
  white-space: nowrap;
}
.mainnav-link:hover, .more-btn:hover { background: var(--bg-panel); color: var(--text); }
.mainnav-link[aria-current="page"], .more-btn.is-current { color: var(--text); }
.mainnav-link[aria-current="page"]::after, .more-btn.is-current::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: -10px;
  height: 2px;
  border-radius: var(--radius-xs);
  background: var(--grad);
}
.more, .language-picker { position: relative; }
.more-btn svg { width: 14px; height: 14px; }
.more-panel, .language-panel {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  width: 248px;
  padding: 8px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
  z-index: 45;
}
.more-label { margin: 4px 10px 6px; font-family: var(--font-mono); font-size: 11px; color: var(--text-muted); letter-spacing: var(--tracking-label); }
.more-panel a, .language-panel a { display: flex; flex-direction: column; justify-content: center; min-height: 44px; padding: 8px 10px; border-radius: var(--radius-sm); text-decoration: none; color: var(--text); font-size: 14px; line-height: 1.4; }
.more-panel a small { color: var(--text-muted); font-size: 12px; }
.more-panel a:hover, .language-panel a:hover, .language-panel a[aria-current="true"] { background: var(--bg-panel); color: var(--text); }
.header-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.lang, .hamburger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 44px;
  padding: 7px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text-muted);
  font: inherit;
  font-size: 13.5px;
  text-decoration: none;
}
.lang svg { width: 15px; height: 15px; }
.lang-caret { font-size: 11px; }
.lang-short { display: none; }
.hamburger { display: none; min-width: 44px; padding: 10px; }
.hamburger svg { width: 22px; height: 22px; }
.mobile-nav { display: none; }
.nav-veil { position: fixed; inset: var(--header-height) 0 0; z-index: 39; border: 0; padding: 0; background: var(--veil); color: var(--text); }
.static-more > summary { list-style: none; }
.static-more > summary::-webkit-details-marker { display: none; }
.site-footer { border-top: 1px solid var(--border); padding-top: 56px; padding-bottom: 28px; background: var(--bg-panel); color: var(--text); }
.footer-grid { display: grid; grid-template-columns: 1.25fr 0.85fr 1.5fr 0.8fr; gap: 32px; }
.footer-grid > * { min-width: 0; }
.footer-brand p { max-width: 280px; margin: 16px 0 0; color: var(--text-muted); font-size: 14px; }
.footer-title { margin: 0 0 14px; font-size: 14px; font-weight: var(--weight-medium); }
.footer-links { list-style: none; padding: 0; margin: 0; }
.footer-links li { margin: 0 0 8px; }
.footer-links a { font-size: 13px; color: var(--text-muted); text-decoration: none; overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--accent-dark); text-decoration: underline; }
.footer-links a[aria-current="true"] { color: var(--text); }
.footer-bottom { margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--border); font-size: 12px; color: var(--text-muted); }
.prose { min-width: 0; line-height: 1.85; }
.prose h2 { margin-top: 48px; scroll-margin-top: 100px; }
.prose h3 { margin-top: 30px; }
.prose a:not([class*="btn"]):not([class*="button"]) { color: var(--accent-dark); }
.prose :not(pre) > code { padding: 2px 5px; border-radius: var(--radius-xs); background: var(--bg-panel-2); color: var(--text); font-size: 0.9em; }
.prose pre { padding: 20px; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--bg-panel); color: var(--text); font-size: 13px; }
.prose li { margin-bottom: 8px; }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
.reveal-ready .reveal { transition: opacity var(--motion-reveal) ease, transform var(--motion-reveal) ease; }
@media (max-width: 1100px) {
  .mainnav { display: none; }
  .header-tools { margin-left: auto; }
  .hamburger { display: inline-flex; }
  .mobile-nav:not([hidden]) { display: block; position: absolute; top: 100%; left: 0; right: 0; z-index: 42; max-height: calc(100dvh - var(--header-height)); overflow-y: auto; overscroll-behavior: contain; padding: 16px var(--gutter) 24px; border-bottom: 1px solid var(--border); background: var(--bg); color: var(--text); box-shadow: var(--shadow-card); }
  .mobile-nav ul { margin: 0; padding: 0; list-style: none; }
  .mobile-nav a { display: flex; align-items: center; min-height: 46px; width: 100%; padding: 10px 12px; border-radius: var(--radius-sm); text-decoration: none; color: var(--text); }
  .mobile-nav a:hover, .mobile-nav a[aria-current] { background: var(--bg-panel); color: var(--text); }
  .mobile-nav-label { margin: 18px 12px 6px; color: var(--text-muted); font-size: 12px; }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  :root { --gutter: 20px; --size-h1: clamp(24px, 4.4vw, 30px); --size-h2: 24px; --size-h3: 19px; --section-space: 64px; }
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .split { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .topbar-inner { gap: 8px; }
  .brand { font-size: 15px; gap: 7px; }
  .brand-mark { width: 26px; height: 26px; }
  .header-tools { margin-left: auto; gap: 6px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .lang { padding-inline: 10px; }
  .language-panel { width: 188px; }
  .grid { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .card, .panel { padding: 20px; }
  .tilt, [data-tilt] { transform: none !important; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}