html {
  scroll-behavior: smooth;
}

body {
  margin: 40px auto;
  max-width: 650px;
  line-height: 1.6;
  font-size: 18px;
  color: #444;
  padding: 0 10px;
  background-color: #f5f5f5;
}

main {
  background: white;
  padding: 2rem;
  border-radius: 8px;
}

h1, h2, h3 {
  line-height: 1.2;
}

nav {
  margin-bottom: 2rem;
}

nav a {
  margin-right: 1rem;
  text-decoration: none;
  color: #444;
}

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

nav a.active {
  font-weight: bold;
}

footer {
  margin-top: 2rem;
  font-size: 0.9em;
  color: #666;
}