:root {
  color-scheme: light;
  --bg: #f7f6f2;
  --card: #ffffff;
  --ink: #1f2328;
  --muted: #5d6673;
  --line: #e5e1d8;
  --accent: #3d5a40;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, #fffaf0, var(--bg) 48%, #ece9e0);
  color: var(--ink);
  line-height: 1.72;
}
main { width: min(880px, calc(100% - 32px)); margin: 48px auto; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 32px;
  box-shadow: 0 16px 40px rgba(31, 35, 40, 0.08);
}
h1 { margin-top: 0; line-height: 1.25; letter-spacing: -0.02em; }
h2 { margin-top: 28px; }
a { color: var(--accent); font-weight: 650; }
nav { display: grid; gap: 12px; margin: 24px 0; }
.small { color: var(--muted); font-size: 0.92rem; }
.notice { border-left: 4px solid var(--accent); padding-left: 16px; color: var(--muted); }
footer { margin-top: 28px; color: var(--muted); font-size: 0.9rem; }
@media (max-width: 600px) { main { margin: 24px auto; } .card { padding: 22px; border-radius: 18px; } }