body {
  font-family: Arial, sans-serif;
  background-color: #f6f9fc;
  color: #333;
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

header, main, footer {
  max-width: 860px;
  margin: 20px auto;
  background: white;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 0 6px rgba(0,0,0,0.1);
}

h1, h2 {
  color: #2c4a7a;
}

code {
  background: #eee;
  padding: 2px 4px;
  border-radius: 4px;
}

ul {
  margin-left: 20px;
}