body {
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  background-color: #f9f9f9;
  margin: 0;
  padding: 0;
}

main {
  max-width: 800px;
  margin: 40px auto;
  background: #fff;
  padding: 2rem;
  box-shadow: 0 0 10px rgba(0,0,0,0.05);
}

h1, h2, h3 {
  color: #003366;
}

a {
  color: #007acc;
  text-decoration: none;
}

ul {
  padding-left: 1.2em;
}