:root {
  color-scheme: dark;
  --c-bg: #0F0F0F;
  --c-panel: #181818;
  --c-panel-2: #202020;
  --c-line: #2A2A2A;
  --c-line-strong: #363636;
  --c-dot: #3A3A3A;
  --c-side-active: #2D2D2D;
  --c-accent: #8F5BFF;
  --c-accent-dark: #6A35E8;
  --c-accent-soft: rgba(143, 91, 255, 0.13);
  --c-accent-ring: rgba(143, 91, 255, 0.34);
  --c-accent-glow: rgba(143, 91, 255, 0.17);
  --c-accent-cast: rgba(106, 53, 232, 0.45);
  --c-text: #E9E9E9;
  --c-text-2: #BDBDBD;
  --c-muted: #9B9B9B;
  --c-faint: #686868;
  --c-white: #FFFFFF;
  --c-highlight: rgba(255, 255, 255, 0.05);
  --c-btn-sheen: rgba(255, 255, 255, 0.18);
  --c-success: #3FCF7A;
  --c-warn: #E0A93A;
  --c-error: #E5534B;
  --c-transparent: transparent;
  --c-veil: rgba(0, 0, 0, 0.72);
  --grad-accent: linear-gradient(135deg, var(--c-accent) 0%, var(--c-accent-dark) 100%);
  --shadow-window: inset 0 1px 0 var(--c-highlight), 0 22px 44px -14px rgba(0, 0, 0, 0.6), 0 64px 120px -24px rgba(0, 0, 0, 0.7);
  --shadow-phone: inset 0 1px 0 var(--c-highlight), 0 14px 26px rgba(0, 0, 0, 0.55), 0 40px 80px -12px rgba(0, 0, 0, 0.85);
  --shadow-note: 0 10px 26px -10px rgba(0, 0, 0, 0.7);
  --shadow-btn: inset 0 1px 0 var(--c-btn-sheen), 0 10px 24px -10px var(--c-accent-cast);
  --shadow-fab: inset 0 1px 0 var(--c-btn-sheen), 0 8px 18px -6px var(--c-accent-cast);
  --r-ctl: 6px;
  --r-panel: 10px;
  --r-pill: 999px;
  --r-round: 50%;
  --r-phone: 28px;
  --r-screen: 22px;
  --f-display: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --f-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --fs-body: 15px;
  --fs-small: 13px;
  --fs-micro: 12px;
  --fs-h1: clamp(34px, 3.1vw, 44px);
  --fs-h2: clamp(25px, 2.5vw, 32px);
  --fs-h3: 21px;
  --weight-normal: 400;
  --weight-medium: 500;
  --lh-body: 1.75;
  --lh-heading: 1.2;
  --tracking-heading: -0.02em;
  --nav-h: 64px;
  --wrap: 1200px;
  --reading: 800px;
  --header-wrap: 1280px;
  --gutter: 32px;
  --space-section: 96px;
  --space-panel: 28px;
  --motion-fast: 160ms;
  --motion-reveal: 650ms;
  --ease-out: cubic-bezier(.2, .7, .2, 1);
  --z-header: 50;
  --z-veil: 40;
  --z-fab: 30;
}

*, *::before, *::after { box-sizing: border-box; }
html { background: var(--c-bg); scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--f-body);
  font-size: var(--fs-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
html.nav-open { overflow: hidden; }
[hidden] { display: none !important; }
a { color: var(--c-accent); text-decoration-thickness: 1px; text-underline-offset: 4px; }
a:hover { text-decoration: underline; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, input, select, textarea {
  color: var(--c-text);
  background: var(--c-bg);
}
button { border: 1px solid var(--c-line); border-radius: var(--r-ctl); }
button:disabled { cursor: not-allowed; }
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: var(--r-ctl);
}
img, svg { display: block; max-width: 100%; }
img { height: auto; }
svg, .icon, .status-dot { flex-shrink: 0; }
svg { color: inherit; }
h1, h2, h3, h4 {
  font-family: var(--f-display);
  font-weight: var(--weight-medium);
  line-height: var(--lh-heading);
  letter-spacing: var(--tracking-heading);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }
p { margin-top: 0; }
strong, b { font-weight: var(--weight-medium); }
code, pre, kbd, samp { font-family: var(--f-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  min-width: 0;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--c-line);
  border-radius: var(--r-ctl);
  background: var(--c-bg);
  color: var(--c-text-2);
  font-size: var(--fs-small);
  line-height: 1.8;
  tab-size: 2;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
blockquote { margin-inline: 0; }
hr { border: 0; border-top: 1px solid var(--c-line); margin-block: 40px; }
:where(section, article, aside, nav, div, li) { min-width: 0; }
:where(.grid, .two-column, .footer-grid) > * { min-width: 0; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.keep { white-space: nowrap; }
.muted { color: var(--c-muted); }
.accent { color: var(--c-accent); }
.mono { font-family: var(--f-mono); }
.wrap {
  width: 100%;
  max-width: calc(var(--wrap) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading {
  width: 100%;
  max-width: calc(var(--reading) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section {
  padding-top: var(--space-section);
  padding-bottom: var(--space-section);
  border-top: 1px solid var(--c-line);
}
.section-head { margin-bottom: 40px; max-width: 760px; }
.section-head h2 { margin-top: 14px; margin-bottom: 16px; }
.section-head p { color: var(--c-muted); }
.eyebrow { font-family: var(--f-mono); font-size: var(--fs-micro); color: var(--c-muted); }
.two-column { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.stack > * + * { margin-top: 20px; }
.cluster { display: flex; align-items: center; flex-wrap: wrap; gap: 12px; }
.prose { line-height: 1.85; overflow-wrap: break-word; }
.prose h2 { margin-top: 64px; margin-bottom: 24px; }
.prose h3 { margin-top: 36px; }
.prose p, .prose ul, .prose ol { margin-bottom: 24px; }
.prose li + li { margin-top: 8px; }
.prose :not(pre) > code {
  background: var(--c-panel-2);
  color: var(--c-text);
  border-radius: var(--r-ctl);
  padding: 2px 5px;
  font-size: .9em;
}
.prose img { margin-block: 28px; }
.panel, .card {
  padding: var(--space-panel);
  background: var(--c-panel);
  color: var(--c-text);
  border: 1px solid var(--c-line);
  border-radius: var(--r-panel);
  box-shadow: var(--shadow-note);
}
.panel h3, .card h3 { margin-top: 0; }
.panel p, .card p { color: var(--c-muted); }
.decorative-section, .hero, [data-hero-visual] { overflow-x: clip; }
.reveal { opacity: 1; transform: none; }
html.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(14px); }
html.reveal-ready .reveal {
  transition: opacity var(--motion-reveal) var(--ease-out), transform var(--motion-reveal) var(--ease-out);
}
html.reveal-ready .reveal.shown { opacity: 1; transform: none; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 20px;
  border: 1px solid var(--c-transparent);
  border-radius: var(--r-ctl);
  font-size: var(--fs-body);
  font-weight: var(--weight-medium);
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
  background: var(--c-transparent);
  color: var(--c-text);
  transition: border-color var(--motion-fast), box-shadow var(--motion-fast);
}
.btn svg { width: 17px; height: 17px; }
.btn:hover { text-decoration: none; }
.btn--primary { background: var(--grad-accent); color: var(--c-white); box-shadow: var(--shadow-btn); }
.btn--primary:hover, .btn--primary.is-hover { box-shadow: var(--shadow-btn), 0 0 0 3px var(--c-accent-soft); }
.btn--ghost { border-color: var(--c-line-strong); background: var(--c-transparent); color: var(--c-text); }
.btn--ghost:hover, .btn--ghost.is-hover { background: var(--c-panel); color: var(--c-text); }
.btn--text { color: var(--c-accent); background: var(--c-transparent); padding-inline: 0; }
.btn:active, .btn.is-active { box-shadow: inset 0 0 0 2px var(--c-accent-ring); }
.btn.is-focus { outline: 2px solid var(--c-accent); outline-offset: 3px; }
.btn:disabled, .btn[aria-disabled="true"] {
  background: var(--c-panel-2);
  color: var(--c-muted);
  border-color: var(--c-line);
  box-shadow: none;
}
.cta-row { margin-top: 26px; display: flex; align-items: center; flex-wrap: wrap; gap: 12px; }
.cta-sep { width: 1px; height: 24px; margin-inline: 14px; background: var(--c-line); }

#site-header { position: relative; z-index: var(--z-header); }
.topbar {
  position: relative;
  width: 100%;
  max-width: min(100%, calc(var(--header-wrap) + var(--gutter) * 2));
  height: var(--nav-h);
  padding-inline: var(--gutter);
  margin-inline: auto;
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--c-bg);
  color: var(--c-text);
  z-index: var(--z-header);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  font-family: var(--f-display);
  font-size: 16px;
  font-weight: var(--weight-medium);
  letter-spacing: -.01em;
  color: var(--c-text);
  text-decoration: none;
}
.brand:hover { text-decoration: none; }
.brand-mark { width: 26px; height: 26px; flex-shrink: 0; }
.mainnav { margin-left: 40px; min-width: 0; }
.mainnav ul {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 2px;
}
.mainnav li { flex-shrink: 0; }
.mainnav a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 4px 13px;
  border-radius: var(--r-pill);
  font-size: 14px;
  color: var(--c-muted);
  text-decoration: none;
  white-space: nowrap;
}
.mainnav a:hover { color: var(--c-text); }
.mainnav a[aria-current="page"], .mobile-drawer a[aria-current="page"] {
  color: var(--c-text);
  background: var(--c-accent-soft);
  box-shadow: inset 0 0 0 1px var(--c-accent-ring);
}
.header-tools { display: flex; align-items: center; gap: 8px; margin-left: auto; flex-shrink: 0; }
.language-picker { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 34px;
  padding: 6px 12px;
  border: 1px solid var(--c-line);
  border-radius: var(--r-ctl);
  font-size: 13.5px;
  background: var(--c-bg);
  color: var(--c-text-2);
  text-decoration: none;
  white-space: nowrap;
}
.lang svg { width: 15px; height: 15px; color: var(--c-muted); }
.lang-short { display: none; }
.caret { color: var(--c-muted); font-size: 11px; }
.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  width: 190px;
  padding: 6px;
  margin: 0;
  list-style: none;
  border: 1px solid var(--c-line);
  border-radius: var(--r-ctl);
  background: var(--c-panel);
  color: var(--c-text);
  box-shadow: var(--shadow-note);
}
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 12px; color: var(--c-text-2); text-decoration: none; border-radius: var(--r-ctl); }
.language-menu a:hover { background: var(--c-panel-2); color: var(--c-text); }
.language-menu a[aria-current="true"] { color: var(--c-accent); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; background: var(--c-bg); color: var(--c-text); }
.menu-toggle svg { width: 21px; height: 21px; }
.mobile-drawer {
  position: absolute;
  left: 0;
  right: 0;
  top: var(--nav-h);
  padding: 16px var(--gutter) 24px;
  max-height: calc(100dvh - var(--nav-h));
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--c-panel);
  color: var(--c-text);
  border-bottom: 1px solid var(--c-line);
  box-shadow: var(--shadow-note);
}
.mobile-drawer ul { list-style: none; padding: 0; margin: 0; }
.mobile-drawer a {
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 46px;
  padding: 12px 16px;
  border-radius: var(--r-ctl);
  color: var(--c-text-2);
  text-decoration: none;
}
.mobile-drawer a:hover { background: var(--c-panel-2); color: var(--c-text); }
.drawer-languages { border-top: 1px solid var(--c-line); margin-top: 16px; padding-top: 12px; }
.drawer-languages p { padding-inline: 16px; margin-bottom: 8px; color: var(--c-muted); font-size: var(--fs-small); }
.nav-veil {
  position: fixed;
  inset: var(--nav-h) 0 0;
  border: 0;
  border-radius: 0;
  background: var(--c-veil);
  color: var(--c-text);
  z-index: var(--z-veil);
}
.static-language { position: relative; }
.static-language summary { list-style: none; cursor: pointer; }
.static-language summary::-webkit-details-marker { display: none; }
.preview-mobile { display: none; }

.site-footer {
  padding-top: 72px;
  padding-bottom: 32px;
  border-top: 1px solid var(--c-line);
  background: var(--c-bg);
  color: var(--c-text);
}
.footer-grid { display: grid; grid-template-columns: 1.3fr .8fr 1.4fr .7fr; gap: 40px; }
.footer-brand p { max-width: 310px; color: var(--c-muted); margin-top: 20px; font-size: 14px; line-height: 1.8; }
.footer-title { margin: 0 0 18px; font-size: 14px; font-weight: var(--weight-medium); }
.footer-list { padding: 0; margin: 0; list-style: none; }
.footer-list li + li { margin-top: 10px; }
.footer-list a { color: var(--c-muted); font-size: var(--fs-small); text-decoration: none; overflow-wrap: anywhere; }
.footer-list a:hover { color: var(--c-text); text-decoration: underline; }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--c-line); color: var(--c-muted); font-size: var(--fs-small); }
.footer-bottom p { margin: 0; }
.footer-bottom a { color: var(--c-muted); }

@media (max-width: 1279px) {
  .mainnav { display: none; }
  .menu-toggle { display: inline-flex; }
  .header-tools { margin-left: auto; }
  .preview-mobile { display: block; }
  .preview-mobile > summary { list-style: none; }
  .preview-mobile > summary::-webkit-details-marker { display: none; }
  .preview-mobile[open] .mobile-drawer { display: block; }
}
@media (min-width: 1280px) {
  .mobile-drawer, .nav-veil { display: none; }
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  :root { --fs-h1: clamp(24px, 6.4vw, 30px); --space-section: 64px; --gutter: 20px; --space-panel: 20px; }
  .two-column { grid-template-columns: 1fr; gap: 24px; }
  .cta-sep { display: none; }
}
@media (max-width: 640px) {
  .tilt, .is-tilted, [data-tilt] { transform: none !important; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .site-footer { padding-top: 48px; }
  .prose h2 { margin-top: 48px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .header-tools { margin-left: auto; }
  .brand { font-size: 14px; gap: 7px; }
  .lang { min-height: 44px; padding-inline: 10px; }
}
@media (max-width: 360px) {
  :root { --gutter: 16px; }
  .brand-mark { width: 23px; height: 23px; }
  .header-tools { gap: 5px; }
  .lang svg { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}