:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --text: #20242a;
  --muted: #5b6573;
  --border: #d8dee6;
  --accent: #0b6bcb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 24px;
}

header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

h1, h2, h3 {
  margin-top: 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
  margin-bottom: 16px;
}

nav a {
  margin-right: 14px;
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

nav a:hover {
  text-decoration: underline;
}

code, pre {
  font-family: Consolas, "Courier New", monospace;
}

pre {
  background: #111827;
  color: #f3f4f6;
  border-radius: 8px;
  padding: 12px;
  overflow-x: auto;
}

small {
  color: var(--muted);
}

ul {
  margin-top: 8px;
}