:root {
  color-scheme: light dark;
  --accent: #0e7c86;
  --background: #f5fafb;
  --surface: #ffffff;
  --text: #172326;
  --muted: #526368;
  --border: #d7e5e7;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #101719;
    --surface: #172124;
    --text: #edf7f8;
    --muted: #adc0c4;
    --border: #34484c;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--text);
  background: var(--background);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", sans-serif;
  line-height: 1.75;
}

main {
  width: min(760px, calc(100% - 32px));
  margin: 40px auto;
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
}

h1, h2 { line-height: 1.35; }
h1 { margin-top: 0; font-size: clamp(1.8rem, 5vw, 2.5rem); }
h2 { margin-top: 2rem; font-size: 1.25rem; }
a { color: var(--accent); }
.lead { color: var(--muted); font-size: 1.05rem; }
.notice { padding: 16px; border-left: 4px solid var(--accent); background: color-mix(in srgb, var(--accent) 8%, transparent); }
nav { display: flex; flex-wrap: wrap; gap: 12px 20px; margin-top: 32px; padding-top: 20px; border-top: 1px solid var(--border); }
footer { margin-top: 32px; color: var(--muted); font-size: .85rem; }