:root {
  color-scheme: light dark;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  --accent: #356859;
  --surface: #f5f7f6;
  --text: #17211e;
  --muted: #50605b;
}

* { box-sizing: border-box; }
body { margin: 0; color: var(--text); background: white; }
main { max-width: 760px; margin: 0 auto; padding: 48px 24px 72px; }
h1, h2 { line-height: 1.2; }
h1 { margin-bottom: 8px; }
h2 { margin-top: 32px; }
a { color: var(--accent); }
.summary { color: var(--muted); font-size: 1.08rem; }
.card { background: var(--surface); border-radius: 14px; padding: 20px; margin: 24px 0; }
.button { display: inline-block; background: var(--accent); color: white; padding: 10px 16px; border-radius: 8px; text-decoration: none; font-weight: 650; }
footer { margin-top: 48px; color: var(--muted); font-size: .9rem; }

@media (prefers-color-scheme: dark) {
  :root { --surface: #1d2925; --text: #edf5f2; --muted: #b5c5bf; --accent: #79c7ad; }
  body { background: #111815; }
  .button { color: #10231d; }
}