:root {
  --bg: #ffffff;
  --surface: #f4f6f8;
  --text: #1c2430;
  --muted: #5b6675;
  --accent: #2563eb;
  --accent-text: #ffffff;
  --border: #e1e6ec;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f141a;
    --surface: #18202a;
    --text: #e6ebf1;
    --muted: #9aa6b5;
    --accent: #5b8def;
    --accent-text: #0f141a;
    --border: #263040;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

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

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 16px max(16px, calc((100% - 960px) / 2));
  border-bottom: 1px solid var(--border);
}

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

.site-header nav { display: flex; gap: 20px; }
.site-header nav a { color: var(--muted); text-decoration: none; }
.site-header nav a:hover { color: var(--accent); }

main, .site-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 16px;
}

section { padding: 48px 0; }

.hero { padding: 80px 0 64px; }
.hero h1 { font-size: clamp(2rem, 5vw, 3.2rem); line-height: 1.15; margin: 0 0 16px; }
.hero p { max-width: 560px; color: var(--muted); font-size: 1.1rem; margin: 0 0 28px; }

.button {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 600;
  text-decoration: none;
}
.button:hover { opacity: 0.9; }

h2 { margin: 0 0 16px; font-size: 1.6rem; }

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.card {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
}
.card h3 { margin: 0 0 8px; }
.card p { margin: 0; color: var(--muted); }

.site-footer {
  padding: 24px 16px;
  margin-top: 24px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}