:root {
  --bg: #f7f7fb; --card: #ffffff; --text: #16161d; --muted: #5d6070; --line: #e4e5ee;
  --accent: #4f46e5; --accent-2: #0ea5a4; --accent-ink: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0d0e14; --card: #161822; --text: #ecedf3; --muted: #9a9db0; --line: #262938; --accent: #7c75ff; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif; }
a { color: var(--accent); }
main { max-width: 960px; margin: 0 auto; padding: 0 20px; }
.narrow { max-width: 720px; }
.center { text-align: center; padding-top: 12vh; }
header.top { display: flex; align-items: center; justify-content: space-between; max-width: 960px;
  margin: 0 auto; padding: 20px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px;
  color: var(--text); text-decoration: none; }
.brand img { width: 32px; height: 32px; }
nav.links a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 15px; }
nav.links a:hover { color: var(--text); }
.hero { text-align: center; padding: 64px 0 40px; }
.hero img { width: 112px; height: 112px; filter: drop-shadow(0 18px 40px rgba(79, 70, 229, .35)); }
.hero h1 { font-size: clamp(34px, 6vw, 52px); line-height: 1.1; margin: 28px 0 14px; letter-spacing: -.02em; }
.hero p { color: var(--muted); font-size: 19px; max-width: 560px; margin: 0 auto 30px; }
.btn { display: inline-block; background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: var(--accent-ink);
  text-decoration: none; padding: 13px 26px; border-radius: 12px; font-weight: 600; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 16px; padding: 24px 0 56px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 22px; }
.card .ico { font-size: 26px; }
.card h3 { margin: 10px 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.doc { padding: 32px 0 64px; }
.doc h1 { font-size: 34px; margin-bottom: 4px; letter-spacing: -.01em; }
.doc .meta { color: var(--muted); margin-top: 0; }
.doc h2 { font-size: 21px; margin-top: 34px; }
.doc li { margin: 6px 0; }
.note { background: var(--card); border: 1px solid var(--line); border-left: 4px solid var(--accent);
  border-radius: 10px; padding: 14px 18px; }
footer { border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; text-align: center; padding: 26px 20px; }
footer a { color: var(--muted); margin: 0 8px; }