:root {
  --bg: #0f172a;
  --surface: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --border: #334155;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 24px;
}

header {
  border-bottom: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.9);
  position: sticky;
  top: 0;
  backdrop-filter: blur(8px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

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

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 14px;
  font-size: 14px;
}

nav a:hover, nav a.active { color: var(--accent); }

.card {
  background: rgba(30, 41, 59, 0.75);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px;
  margin: 16px 0;
}

h1, h2, h3 { line-height: 1.25; margin-top: 0; }
h1 { font-size: 30px; }
h2 { margin-top: 24px; }

p, li { color: var(--text); }
.small { color: var(--muted); font-size: 14px; }

.cta {
  display: inline-block;
  background: rgba(56, 189, 248, 0.16);
  border: 1px solid rgba(56, 189, 248, 0.4);
  color: var(--accent);
  text-decoration: none;
  border-radius: 10px;
  padding: 10px 14px;
  font-weight: 600;
  margin-right: 10px;
}

footer {
  border-top: 1px solid var(--border);
  margin-top: 28px;
  color: var(--muted);
  font-size: 14px;
}

code {
  background: #111827;
  border: 1px solid #1f2937;
  border-radius: 6px;
  padding: 2px 6px;
}