:root {
  color-scheme: light dark;
  --background: #f5f5f7;
  --surface: rgba(255, 255, 255, 0.82);
  --text: #171717;
  --secondary: #6b6b73;
  --border: rgba(0, 0, 0, 0.09);
  --accent: #1683ff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #111113;
    --surface: rgba(30, 30, 33, 0.92);
    --text: #f5f5f7;
    --secondary: #a3a3ad;
    --border: rgba(255, 255, 255, 0.12);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  line-height: 1.6;
}

a { color: var(--accent); }

.shell {
  width: min(720px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0 64px;
}

header {
  margin-bottom: 32px;
}

.brand {
  color: var(--text);
  font-size: 1.15rem;
  font-weight: 700;
  text-decoration: none;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 12px;
  font-size: 0.95rem;
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(2rem, 7vw, 3.25rem);
  letter-spacing: -0.04em;
  line-height: 1.08;
}

h2 {
  margin: 36px 0 10px;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

p, li { color: var(--secondary); }

.lead {
  margin-top: 0;
  font-size: 1.1rem;
}

.card {
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: var(--surface);
  backdrop-filter: blur(18px);
}

footer {
  margin-top: 48px;
  color: var(--secondary);
  font-size: 0.9rem;
}

footer a { margin-right: 16px; }