:root {
  --bg: #FFFFFF;
  --bg-panel: #F5F7FC;
  --bg-panel-2: #EBF0F9;
  --border: #DCE3F0;
  --accent: #2350C8;
  --accent-dark: #183A96;
  --text: #121A2E;
  --text-muted: #5A6478;
  --success: #1E8A5A;
  --warn: #B7791F;
  --error: #C83A3A;
  --hairline: #E3E8F2;
  --skeleton: #E2E8F3;
  --skeleton-soft: #EDF1F8;
  --chrome-dot: #D4DAE5;
  --rim: #C8D5F2;
  --accent-soft: #E8EEFB;
  --on-accent: #FFFFFF;
  --on-accent-muted: rgba(255,255,255,.86);
  --sidebar-active: rgba(8,20,66,.40);
  --sidebar-edge: rgba(255,255,255,.10);
  --island: #121A2E;
  --veil: rgba(18,26,46,.34);
  --clear: transparent;
  --shadow-xs: 0 1px 2px rgba(18,26,46,.06);
  --shadow-card: 0 1px 2px rgba(18,26,46,.05),0 12px 30px -14px rgba(18,26,46,.16);
  --shadow-current: 0 0 0 1px #2350C8,0 8px 18px -12px rgba(35,80,200,.55);
  --shadow-window: 0 2px 6px rgba(18,26,46,.06),0 30px 64px -26px rgba(24,58,150,.30);
  --shadow-float: 0 4px 12px rgba(18,26,46,.08),0 44px 84px -30px rgba(24,58,150,.40);
  --shadow-btn: 0 1px 2px rgba(24,58,150,.28),0 10px 22px -10px rgba(35,80,200,.62);
  --shadow-knob: 0 1px 2px rgba(18,26,46,.22);
  --font-display: "Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe 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;
  --r-xs: 6px;
  --r-sm: 8px;
  --r-control: 10px;
  --r-md: 12px;
  --r-lg: 20px;
  --r-xl: 24px;
  --r-phone: 28px;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-skeleton: 4px;
  --gutter: 48px;
  --content-max: 1344px;
  --reading-max: 860px;
  --header-max: 1280px;
  --head-h: 72px;
  --peek: 34px;
  --section-space: 96px;
  --motion-fast: .2s;
  --motion-reveal: .55s;
  --tab-duration: 8s;
  --layer-header: 30;
  --layer-veil: 31;
  --layer-drawer: 32;
  --layer-fab: 20;
}
*,*::before,*::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
html,body { margin: 0; min-width: 0; }
html.nav-open { overflow: hidden; }
body {
  position: relative;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
[hidden] { display: none !important; }
img,svg,video { max-width: 100%; }
img { height: auto; }
button,input,select,textarea { font: inherit; }
button,a,input,select,textarea,summary { -webkit-tap-highlight-color: var(--clear); }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
a { color: var(--accent); text-underline-offset: .2em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
h1,h2,h3,h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.3;
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: clamp(34px,2.2vw + 16px,48px); line-height: 1.2; letter-spacing: -.01em; }
h2 { font-size: clamp(24px,2.1vw,32px); }
h3 { font-size: 21px; font-weight: 700; }
p { margin-top: 0; }
code,kbd,pre { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; font-size: .9em; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--bg-panel);
  color: var(--text);
  font-size: 13px;
  line-height: 1.8;
  tab-size: 2;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; font-size: inherit; }
hr { border: 0; border-top: 1px solid var(--border); margin-block: 32px; }
::selection { background: var(--accent-soft); color: var(--accent-dark); }
.wrap {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: var(--reading-max); margin-inline: auto; min-width: 0; }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.grid { display: grid; gap: 24px; }
.grid > *, .hero-grid > *, .footer-grid > *, .feature-browser > * { min-width: 0; }
.grid-2 { grid-template-columns: repeat(2,minmax(0,1fr)); }
.grid-3 { grid-template-columns: repeat(3,minmax(0,1fr)); }
.stack > * + * { margin-top: 24px; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-muted); }
.mono { font-family: var(--font-mono); }
.small { font-size: 13px; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.ic {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}
.pi { fill: currentColor; flex-shrink: 0; }
.panel,.card {
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-card);
  min-width: 0;
  padding: 28px;
}
.panel-soft { background: var(--bg-panel); color: var(--text); box-shadow: none; }
.panel-deep { background: var(--bg-panel-2); color: var(--text); }
.card h3 { margin: 0 0 12px; }
.card p:last-child { margin-bottom: 0; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 10px 28px;
  border: 1.5px solid var(--clear);
  border-radius: var(--r-pill);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
  transition: transform var(--motion-fast) ease,box-shadow var(--motion-fast) ease,background-color var(--motion-fast) ease,color var(--motion-fast) ease,border-color var(--motion-fast) ease;
}
.btn .ic { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-1px); text-decoration: none; }
.btn:active,.btn.is-active { transform: translateY(0); box-shadow: var(--shadow-xs); }
.btn-primary { background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-btn); }
.btn-primary:hover,.btn-primary.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn-ghost { padding-inline: 26px; background: var(--bg); color: var(--text); border-color: var(--text); }
.btn-ghost:hover,.btn-ghost.is-hover { border-color: var(--accent); color: var(--accent); }
.btn-small { min-height: 44px; padding: 9px 20px; font-size: 14px; }
.btn:disabled,.btn[aria-disabled="true"] {
  background: var(--bg-panel-2);
  color: var(--text-muted);
  border-color: var(--border);
  box-shadow: none;
  transform: none;
}
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 3px; }
.cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 30px; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 0; padding: 0; list-style: none; }
.tags li,.tag {
  display: inline-flex;
  align-items: center;
  max-width: 100%;
  min-height: 28px;
  padding: 3px 12px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--bg-panel);
  color: var(--text-muted);
  font-size: 12.5px;
  font-weight: 500;
  line-height: 1.5;
  overflow-wrap: anywhere;
}
.site-head,#site-header { position: relative; z-index: var(--layer-header); padding-top: 12px; }
.head-wrap {
  max-width: min(100%,calc(var(--header-max) + var(--gutter) * 2));
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.bar {
  position: relative;
  min-height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 12px 0 16px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-card);
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); flex-shrink: 0; }
.brand img { width: 32px; height: 32px; flex-shrink: 0; }
.brand-name { font-family: var(--font-display); font-weight: 800; font-size: 17px; letter-spacing: -.005em; }
.desktop-nav { margin-left: auto; min-width: 0; }
.nav-list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 0; }
.nav-list li { display: flex; align-items: center; flex-shrink: 0; }
.nav-list li + li::before { content: "·"; margin-inline: 13px; color: var(--text-muted); font-weight: 700; flex-shrink: 0; }
.nav-list a { display: inline-flex; align-items: center; min-height: 44px; font-size: 14.5px; font-weight: 500; text-decoration: none; color: var(--text); }
.nav-list a:hover { color: var(--accent); }
.nav-list a[aria-current="page"] { color: var(--accent); font-weight: 650; }
.head-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.language { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 36px;
  padding: 8px 14px 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--bg-panel);
  color: var(--text);
  font: 500 13.5px/1.3 var(--font-body);
  white-space: nowrap;
}
.lang .ic { width: 15px; height: 15px; color: var(--accent); }
.lang-caret { color: var(--text-muted); font-size: 11px; }
.lang-short { display: none; }
.lang-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  width: 184px;
  margin: 0;
  padding: 8px;
  list-style: none;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-window);
  z-index: var(--layer-drawer);
}
.lang-menu a,.drawer a { display: flex; align-items: center; width: 100%; min-height: 44px; padding: 10px 14px; color: var(--text); text-decoration: none; border-radius: var(--r-sm); }
.lang-menu a:hover,.lang-menu a[aria-current="true"],.drawer a:hover,.drawer a[aria-current] { background: var(--bg-panel); color: var(--accent); }
.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-md);
  background: var(--bg);
  color: var(--accent);
}
.nav-veil { position: fixed; inset: 72px 0 0; border: 0; background: var(--veil); color: var(--text); z-index: var(--layer-veil); }
.drawer {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  max-height: calc(100dvh - 96px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow-window);
  z-index: var(--layer-drawer);
}
.drawer ul { list-style: none; margin: 0; padding: 0; }
.drawer .drawer-languages { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border); }
.site-footer,#site-footer { background: var(--bg-panel); color: var(--text); }
.footer-inner { padding-top: 64px; padding-bottom: 28px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1.5fr 1fr; gap: 36px; }
.footer-brand p { margin: 18px 0 0; max-width: 24em; color: var(--text-muted); font-size: 14px; }
.footer-grid h2 { margin: 0 0 16px; font-size: 14px; font-weight: 700; }
.footer-links { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer-links a { color: var(--text-muted); font-size: 14px; text-decoration: none; overflow-wrap: anywhere; }
.footer-links a:hover { color: var(--accent); text-decoration: underline; }
.footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--text-muted); font-size: 13px; }
.prose { min-width: 0; }
.prose h2 { margin-top: 2.5em; margin-bottom: .8em; scroll-margin-top: 28px; }
.prose h3 { margin-top: 1.8em; }
.prose p,.prose li { line-height: 1.9; }
.prose ul,.prose ol { padding-left: 1.5em; }
.prose img { max-width: 100%; }
.prose > :first-child { margin-top: 0; }
.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; }
.reveal.shown { opacity: 1; transform: none; }
@media (max-width:1360px) {
  :root { --gutter: 32px; }
}
@media (max-width:1024px) {
  .desktop-nav { display: none; }
  .head-tools { margin-left: auto; }
  .hamburger { display: inline-flex; }
  .bar { gap: 12px; }
}
@media (min-width:1025px) {
  .drawer,.nav-veil { display: none !important; }
}
@media (max-width:900px) {
  .footer-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .grid-3 { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (max-width:768px) {
  h1 { font-size: clamp(24px,4.5vw,30px); }
}
@media (max-width:640px) {
  :root { --gutter: 20px; --section-space: 56px; }
  .grid-2,.grid-3,.footer-grid { grid-template-columns: minmax(0,1fr); }
  .bar { padding-inline: 10px; gap: 6px; }
  .brand { gap: 7px; }
  .brand-name { font-size: 15px; }
  .brand img { width: 28px; height: 28px; }
  .head-tools { margin-left: auto; gap: 5px; }
  .lang { min-height: 44px; padding-inline: 10px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .btn { min-height: 48px; padding-inline: 22px; font-size: 15px; }
  .panel,.card { padding: 22px; }
  .tags { flex-direction: row; flex-wrap: wrap; }
  .tilt,[data-tilt] { transform: none !important; }
  .footer-inner { padding-top: 44px; }
}
@media (max-width:360px) {
  :root { --gutter: 16px; }
  .lang .ic { display: none; }
}
@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; }
  .btn:hover { transform: none; }
}