:root {
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #526077;
  --border: #e3e7ef;
  --primary: #2563eb;
  --primary-ink: #ffffff;
  --accent: #16a34a;
  --soft: #eaf1ff;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --card: #111a2e;
    --text: #e6ebf5;
    --muted: #9aa8c0;
    --border: #22304d;
    --primary: #5b8cff;
    --soft: #15244a;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}
a { color: var(--primary); }
img, svg { max-width: 100%; }

.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }

header.top {
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--card) 85%, transparent);
  backdrop-filter: blur(8px);
  position: sticky; top: 0; z-index: 5;
}
header.top .wrap { display: flex; align-items: center; gap: 16px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; color: var(--text); text-decoration: none; }
.brand img { width: 30px; height: 30px; }
header.top nav { margin-inline-start: auto; display: flex; gap: 18px; font-size: 15px; }
header.top nav a { color: var(--muted); text-decoration: none; }
header.top nav a:hover { color: var(--text); }

.hero { padding: 72px 0 56px; }
.hero h1 { font-size: clamp(32px, 5vw, 52px); line-height: 1.15; margin: 0 0 18px; letter-spacing: -0.01em; }
.hero p.lead { font-size: clamp(18px, 2.2vw, 21px); color: var(--muted); max-width: 720px; margin: 0 0 28px; }
.btn {
  display: inline-block; padding: 12px 22px; border-radius: 12px;
  background: var(--primary); color: var(--primary-ink); font-weight: 700; text-decoration: none;
}
.btn.ghost { background: transparent; color: var(--primary); border: 1px solid var(--border); margin-inline-start: 8px; }

section { padding: 40px 0; }
section h2 { font-size: 28px; margin: 0 0 22px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 22px; }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 16px; }
.step { font-size: 13px; font-weight: 800; color: var(--primary); background: var(--soft); border-radius: 999px; padding: 2px 10px; display: inline-block; margin-bottom: 10px; }

.contact { background: var(--card); border: 1px solid var(--border); border-radius: 20px; padding: 32px; text-align: center; }
.contact p { color: var(--muted); }

article.doc { background: var(--card); border: 1px solid var(--border); border-radius: 16px; padding: 32px clamp(20px, 4vw, 44px); margin: 40px auto; max-width: 820px; }
article.doc h1 { margin-top: 0; font-size: 32px; }
article.doc h2 { font-size: 21px; margin: 30px 0 8px; }
article.doc .updated { color: var(--muted); font-size: 15px; }
article.doc li { margin: 4px 0; }

footer { border-top: 1px solid var(--border); margin-top: 48px; padding: 28px 0 40px; color: var(--muted); font-size: 15px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 10px 22px; align-items: center; }
footer a { color: var(--muted); }
footer .spacer { flex: 1; }

@media (max-width: 640px) {
  header.top nav a.hide-sm { display: none; }
  .hero { padding: 48px 0 32px; }
  .btn.ghost { margin: 10px 0 0; }
}