:root {
  --c-bg: #ffffff;
  --c-panel: #f3f4fd;
  --c-panel-2: #f8f8fa;
  --c-panel-3: #e9ebf8;
  --c-border: #e4e6ef;
  --c-border-strong: #cfd2e0;
  --c-accent: #4d5bf0;
  --c-accent-dark: #3843c9;
  --c-accent-soft: rgba(77, 91, 240, 0.10);
  --c-accent-line: rgba(77, 91, 240, 0.28);
  --c-accent-glow: rgba(77, 91, 240, 0.15);
  --c-text: #1b1c22;
  --c-muted: #5c6070;
  --c-faint: #8a8ea0;
  --c-success: #1f9d6b;
  --c-success-ink: #13734d;
  --c-success-soft: rgba(31, 157, 107, 0.12);
  --c-warn: #c98a12;
  --c-warn-ink: #825808;
  --c-error: #d9443a;
  --c-error-ink: #b32c24;
  --c-on-accent: #ffffff;
  --c-clear: transparent;
  --c-veil: rgba(27, 28, 34, 0.28);

  --f-display: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans', 'Microsoft YaHei', sans-serif;
  --f-body: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans', 'Apple SD Gothic Neo', sans-serif;
  --f-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
  --fs-body: 16px;
  --fs-small: 14px;
  --fs-caption: 13px;
  --fs-h1: clamp(34px, 3.4vw, 48px);
  --fs-h2: clamp(24px, 2.2vw, 32px);
  --fs-h3: 24px;
  --weight-display: 800;
  --tracking-title: -0.02em;
  --r-card: 8px;
  --r-btn: 10px;
  --r-shot: 10px;
  --r-focus: 4px;
  --r-pill: 999px;
  --r-circle: 50%;

  --shadow-card: 0 1px 2px rgba(27, 28, 34, 0.04), 0 12px 28px -16px rgba(27, 28, 34, 0.16);
  --shadow-float: 0 1px 2px rgba(27, 28, 34, 0.05), 0 18px 40px -18px rgba(27, 28, 34, 0.24), 0 6px 16px -8px rgba(77, 91, 240, 0.20);
  --shadow-window: 0 0 0 5px rgba(77, 91, 240, 0.06), 0 0 28px rgba(77, 91, 240, 0.22), 0 0 76px rgba(77, 91, 240, 0.12), 0 32px 52px -30px rgba(27, 28, 34, 0.26);
  --shadow-btn: inset 0 1px 0 rgba(255, 255, 255, 0.18), 0 10px 20px -10px rgba(77, 91, 240, 0.60);
  --wrap: 1200px;
  --gutter: 24px;
  --nav-h: 72px;
  --section-space: 140px;
  --ease-out: cubic-bezier(0.2, 0.7, 0.2, 1);
  --duration: 0.2s;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  font: var(--fs-body)/1.6 var(--f-body);
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
main, section, article, aside, nav, div, figure { min-width: 0; }
img { max-width: 100%; }
svg { flex-shrink: 0; vertical-align: middle; }
a { color: inherit; text-underline-offset: 0.2em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
button, a { -webkit-tap-highlight-color: var(--c-accent-soft); }
[hidden] { display: none !important; }
:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 3px;
  border-radius: var(--r-focus);
}
h1, h2, h3 {
  font-family: var(--f-display);
  font-weight: var(--weight-display);
  letter-spacing: var(--tracking-title);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: var(--fs-h1); line-height: 1.12; }
h2 { font-size: var(--fs-h2); line-height: 1.25; }
h3 { font-size: var(--fs-h3); line-height: 1.35; }
p, li, dd { overflow-wrap: break-word; }
code { font-family: var(--f-mono); overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-card);
  background: var(--c-panel-2);
  color: var(--c-text);
  font: var(--fs-caption)/1.85 var(--f-mono);
  overscroll-behavior-inline: contain;
}
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
[id] { scroll-margin-top: 24px; }
.wrap {
  width: 100%;
  max-width: calc(var(--wrap) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: 800px; margin-inline: auto; }
.section { padding-top: var(--section-space); padding-bottom: var(--section-space); }
.section-panel { background: var(--c-panel); color: var(--c-text); }
.section-heading { margin-top: 0; margin-bottom: 40px; }
.eyebrow { margin: 0 0 12px; font-size: var(--fs-small); font-weight: 600; color: var(--c-accent); }
.muted { color: var(--c-muted); }
.accent, .kw { color: var(--c-accent); }
.nowrap { white-space: nowrap; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: absolute;
  top: 8px;
  left: var(--gutter);
  z-index: 100;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  background: var(--c-accent);
  color: var(--c-on-accent);
  border-radius: var(--r-btn);
}
.skip-link:focus { width: auto; height: auto; padding: 10px 16px; overflow: visible; clip-path: none; }
.grid-two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.grid-three { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.stack > * + * { margin-top: 24px; }
.card, .panel {
  padding: 28px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-card);
  background: var(--c-bg);
  color: var(--c-text);
  box-shadow: var(--shadow-card);
}
.card > :first-child, .panel > :first-child { margin-top: 0; }
.card > :last-child, .panel > :last-child { margin-bottom: 0; }
.card p { color: var(--c-muted); }
.prose { line-height: 1.85; }
.prose h2 { margin-top: 64px; margin-bottom: 24px; }
.prose h3 { margin-top: 36px; margin-bottom: 16px; }
.prose p, .prose ul, .prose ol { margin-top: 0; margin-bottom: 24px; }
.prose a { color: var(--c-accent-dark); }
.prose :not(pre) > code {
  padding: 2px 5px;
  background: var(--c-panel);
  color: var(--c-accent-dark);
  border-radius: var(--r-focus);
  font-size: 0.9em;
}

.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  max-width: 100%;
  padding: 12px 22px;
  border: 1px solid var(--c-clear);
  border-radius: var(--r-btn);
  font: 600 var(--fs-body)/1.4 var(--f-body);
  text-align: center;
  text-decoration: none;
  transition: background var(--duration) var(--ease-out), border-color var(--duration) var(--ease-out), transform var(--duration) var(--ease-out);
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--c-accent); color: var(--c-on-accent); box-shadow: var(--shadow-btn); }
.btn-primary:hover, .btn-primary.is-hover { background: var(--c-accent-dark); color: var(--c-on-accent); transform: translateY(-1px); }
.btn-ghost { background: var(--c-bg); color: var(--c-text); border-color: var(--c-border); }
.btn-ghost:hover, .btn-ghost.is-hover { background: var(--c-panel-2); color: var(--c-text); border-color: var(--c-border-strong); }
.btn:active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] {
  background: var(--c-panel-2);
  color: var(--c-muted);
  border-color: var(--c-border);
  box-shadow: none;
  transform: none;
}
.btn.is-focus { outline: 2px solid var(--c-accent); outline-offset: 3px; }

.masthead { position: relative; z-index: 60; height: var(--nav-h); background: var(--c-bg); color: var(--c-text); }
.masthead-in {
  width: 100%;
  max-width: min(100%, calc(1280px + var(--gutter) * 2));
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--c-text); text-decoration: none; flex-shrink: 0; }
.brand-mark { width: 32px; height: 32px; border-radius: var(--r-circle); flex-shrink: 0; display: block; }
.brand-placeholder { background: var(--c-panel); color: var(--c-accent); border-radius: var(--r-card); box-shadow: inset 0 0 0 1.5px var(--c-accent); }
.brand-name { font: 800 17px/1.3 var(--f-display); letter-spacing: var(--tracking-title); }
.brand-name span { color: var(--c-muted); font-weight: 600; }
.topnav { margin-left: auto; min-width: 0; }
.topnav ul { display: flex; align-items: center; gap: 0; list-style: none; margin: 0; padding: 0; }
.topnav li { display: flex; align-items: center; flex-shrink: 0; }
.topnav li + li::before { content: "·"; color: var(--c-muted); margin-inline: 12px; }
.topnav a { position: relative; display: block; padding: 6px 2px; font-size: 15px; color: var(--c-muted); text-decoration: none; white-space: nowrap; }
.topnav a:hover { color: var(--c-text); }
.topnav a[aria-current="page"] { color: var(--c-text); font-weight: 600; }
.topnav a[aria-current="page"]::after { content: ""; position: absolute; inset-inline: 0; bottom: -1px; height: 2px; background: var(--c-accent); border-radius: var(--r-focus); }
.header-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.language-picker { position: relative; }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 36px;
  padding: 8px 12px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-btn);
  background: var(--c-bg);
  color: var(--c-text);
  font: 500 var(--fs-small)/1.3 var(--f-body);
  white-space: nowrap;
}
.lang:hover { border-color: var(--c-border-strong); background: var(--c-panel-2); color: var(--c-text); }
.lang-short { display: none; }
.language-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  width: 180px;
  padding: 6px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-card);
  background: var(--c-bg);
  color: var(--c-text);
  box-shadow: var(--shadow-float);
}
.language-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 12px; text-decoration: none; border-radius: var(--r-focus); }
.language-menu a:hover, .language-menu a[aria-current="true"] { background: var(--c-panel); color: var(--c-accent-dark); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; border: 1px solid var(--c-border); border-radius: var(--r-btn); background: var(--c-bg); color: var(--c-text); }
.menu-toggle svg { width: 20px; height: 20px; }
.menu-veil { position: fixed; inset: var(--nav-h) 0 0; z-index: 0; border: 0; background: var(--c-veil); color: var(--c-text); }
.mobile-drawer {
  position: absolute;
  top: var(--nav-h);
  inset-inline: 0;
  z-index: 2;
  max-height: calc(100dvh - var(--nav-h));
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 16px var(--gutter) 28px;
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
  background: var(--c-bg);
  color: var(--c-text);
}
.mobile-drawer ul { list-style: none; padding: 0; margin: 0; }
.mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; text-decoration: none; border-radius: var(--r-card); }
.mobile-drawer a:hover, .mobile-drawer a[aria-current] { background: var(--c-panel); color: var(--c-accent-dark); }
.drawer-languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--c-border); }
.drawer-label { margin: 0 16px 8px; font-size: var(--fs-caption); color: var(--c-muted); }

.hero {
  min-height: max(680px, calc(100vh - var(--nav-h) - 64px));
  display: grid;
  align-items: center;
  padding-top: 24px;
  padding-bottom: 40px;
  overflow-x: clip;
}
.hero-grid { display: grid; grid-template-columns: 55fr 45fr; align-items: center; }
.hero-copy { max-width: 600px; position: relative; z-index: 2; }
.hero h1 { margin: 0; font-size: var(--fs-h1); }
.h1-a, .h1-b { display: block; }
.h1-b { color: var(--c-accent); }
.lede { margin: 28px 0 0; max-width: 34em; font-size: 17px; line-height: 1.75; color: var(--c-muted); }
.lede strong { color: var(--c-text); font-weight: 600; }
.devices {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 26px;
  margin: 28px 0 0;
  padding-top: 20px;
  padding-left: 0;
  padding-bottom: 0;
  border-top: 1px solid var(--c-border);
  list-style: none;
}
.devices a { display: inline-flex; align-items: center; gap: 8px; min-height: 28px; color: var(--c-text); font-size: var(--fs-small); font-weight: 500; text-decoration: none; }
.devices a:hover { color: var(--c-accent); }
.devices svg { width: 22px; height: 22px; color: var(--c-accent); }
.devices .pill-slot { margin-left: auto; }

.site-footer { padding-top: 72px; padding-bottom: 112px; border-top: 1px solid var(--c-border); background: var(--c-panel); color: var(--c-text); }
.footer-grid { display: grid; grid-template-columns: 1.3fr 0.8fr 1.4fr 0.8fr; gap: 40px; }
.footer-brand p { max-width: 30em; color: var(--c-muted); font-size: var(--fs-small); }
.footer-title { margin: 0 0 16px; font-size: var(--fs-small); font-weight: 700; }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links a { display: inline-block; padding-top: 6px; padding-bottom: 6px; font-size: var(--fs-small); color: var(--c-muted); text-decoration: none; }
.footer-links a:hover { color: var(--c-accent-dark); text-decoration: underline; }
.footer-links a[aria-current="true"] { color: var(--c-text); font-weight: 600; }
.copyright { margin: 48px 0 0; padding-top: 24px; border-top: 1px solid var(--c-border); font-size: var(--fs-caption); color: var(--c-muted); }

.reveal { opacity: 1; transform: none; }
.reveal-pending { opacity: 0; transform: translateY(16px); transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out); }
.reveal.shown { opacity: 1; transform: none; }

@media (max-width: 1100px) {
  .masthead-in { gap: 16px; }
  .topnav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
}
@media (min-width: 1101px) {
  .mobile-drawer, .menu-veil { display: none !important; }
}
@media (max-width: 960px) {
  .hero { min-height: 0; padding-top: 40px; padding-bottom: 72px; }
  .hero-grid { grid-template-columns: minmax(0, 1fr); }
  .hero-copy { max-width: none; }
  .grid-three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 768px) {
  :root { --fs-h1: clamp(24px, 6vw, 30px); }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .brand { gap: 8px; flex-shrink: 1; min-width: 0; }
  .brand-name { font-size: 15px; min-width: 0; }
  .brand-name span { display: block; font-size: 12px; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .lang { min-height: 44px; }
  .grid-two, .grid-three, .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .card, .panel { padding: 22px; }
  .lede { font-size: var(--fs-body); }
  .devices { gap: 12px 20px; }
  .devices .pill-slot { margin-left: 0; }
  .tilt, [data-tilt] { transform: none !important; }
  .footer-grid { gap: 32px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .reveal, .reveal-pending { opacity: 1; transform: none; }
}