:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #172033;
  --muted: #5d687b;
  --accent: #315efb;
  --border: #e1e6ef;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}
header {
  background: #fff;
  border-bottom: 1px solid var(--border);
}
.header-inner, main, footer {
  width: min(920px, calc(100% - 36px));
  margin: 0 auto;
}
.header-inner {
  padding: 22px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}
.brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}
nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 18px;
}
nav a:hover { color: var(--accent); }
main { padding: 58px 0 70px; }
.hero, section {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 34px;
  margin-bottom: 22px;
}
h1 { font-size: clamp(2rem, 5vw, 3rem); line-height: 1.15; margin: 0 0 14px; }
h2 { margin-top: 0; line-height: 1.25; }
p { margin: 0 0 16px; }
.lead { font-size: 1.15rem; color: var(--muted); }
ul { padding-left: 1.25rem; }
a { color: var(--accent); }
.note {
  background: #f7f9ff;
  border-left: 4px solid var(--accent);
  padding: 14px 18px;
  margin: 22px 0;
}
footer {
  color: var(--muted);
  font-size: .92rem;
  padding: 0 0 34px;
}
.small { color: var(--muted); font-size: .92rem; }
@media (max-width: 650px) {
  .header-inner { align-items: flex-start; flex-direction: column; }
  nav a { margin: 0 14px 0 0; }
  .hero, section { padding: 24px; }
  main { padding-top: 28px; }
}