:root {
  color-scheme: light;
  --brand: #4f83ee;
  --brand-dark: #245fc9;
  --ink: #17243a;
  --muted: #5f6f86;
  --line: #dce4ef;
  --surface: #ffffff;
  --background: #f5f8fc;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", sans-serif;
  line-height: 1.65;
}

header {
  background: linear-gradient(135deg, var(--brand-dark), var(--brand));
  color: #fff;
  padding: 34px 20px;
}

header .wrap, main, footer .wrap { max-width: 880px; margin: 0 auto; }

.brand { font-size: 1.05rem; font-weight: 800; letter-spacing: .02em; }
h1 { margin: 8px 0 2px; font-size: clamp(2rem, 7vw, 3rem); line-height: 1.15; }
.updated { margin: 8px 0 0; opacity: .86; }

main { padding: 28px 18px 52px; }
section {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  margin: 0 0 16px;
  padding: 22px;
  box-shadow: 0 8px 26px rgba(32, 67, 116, .06);
}
h2 { margin: 0 0 10px; font-size: 1.25rem; }
h3 { margin-bottom: 6px; }
p, ul { margin-top: 8px; }
a { color: var(--brand-dark); font-weight: 650; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.button {
  display: inline-block;
  border-radius: 12px;
  padding: 11px 16px;
  background: var(--brand);
  color: #fff;
  text-decoration: none;
}
.button.secondary { background: #edf3ff; color: var(--brand-dark); }
.notice { border-left: 4px solid var(--brand); }

footer { border-top: 1px solid var(--line); background: #fff; padding: 22px 18px 30px; }
footer nav { display: flex; flex-wrap: wrap; gap: 10px 18px; }
footer p { color: var(--muted); font-size: .92rem; }

@media (max-width: 520px) {
  section { padding: 18px; border-radius: 14px; }
}