:root {
  color-scheme: light;
  --ink: #151515;
  --muted: #62656b;
  --line: #e5e5e7;
  --surface: #f5f5f7;
  --accent: #0a84ff;
  --max-width: 960px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.65;
}

a { color: inherit; text-decoration: none; }

.nav {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, .9);
  backdrop-filter: blur(16px);
  position: sticky;
  top: 0;
  z-index: 1;
}

.nav-inner, .container {
  width: min(calc(100% - 40px), var(--max-width));
  margin: 0 auto;
}

.nav-inner {
  min-height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand { font-size: 18px; font-weight: 700; letter-spacing: -.02em; }
.links { display: flex; gap: 20px; font-size: 14px; color: var(--muted); }
.links a:hover { color: var(--accent); }

.hero {
  padding: 96px 0 82px;
  text-align: center;
  background: linear-gradient(180deg, #f5f8fc 0%, #fff 100%);
}

.eyebrow { color: var(--accent); font-size: 15px; font-weight: 700; }
h1, h2, h3 { letter-spacing: -.035em; line-height: 1.15; }
h1 { margin: 12px 0 18px; font-size: clamp(42px, 8vw, 72px); }
h2 { margin: 0 0 18px; font-size: clamp(28px, 5vw, 40px); }
h3 { margin: 0 0 9px; font-size: 20px; }
.lead { max-width: 640px; margin: 0 auto; color: var(--muted); font-size: 20px; }

section { padding: 70px 0; }
section + section { border-top: 1px solid var(--line); }
.section-intro { max-width: 680px; color: var(--muted); margin: 0 0 32px; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.card { border: 1px solid var(--line); border-radius: 18px; padding: 24px; background: #fff; }
.card p, .card li { color: var(--muted); }
.note { border-radius: 18px; padding: 28px; background: var(--surface); }
.note p { margin: 0; }
.cta { display: inline-block; margin-top: 16px; color: var(--accent); font-weight: 600; }

.document { max-width: 760px; }
.document h2 { margin-top: 52px; }
.document h3 { margin-top: 30px; }
.document p, .document li { color: #3d3d40; }
.document ul { padding-left: 24px; }
.lang-divider { margin: 76px 0 0; border: 0; border-top: 1px solid var(--line); }
.faq { border-bottom: 1px solid var(--line); padding: 20px 0; }
.faq:last-child { border-bottom: 0; }
.faq p { color: var(--muted); margin: 8px 0 0; }

footer { padding: 34px 0 44px; color: var(--muted); font-size: 14px; }

@media (max-width: 680px) {
  .nav-inner, .container { width: min(calc(100% - 32px), var(--max-width)); }
  .links { gap: 14px; }
  .hero { padding: 68px 0 58px; }
  section { padding: 50px 0; }
  .grid { grid-template-columns: 1fr; }
  .lead { font-size: 18px; }
}