body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #fafafa;
  color: #333;
}

header {
  background-color: #1e90ff;
  color: white;
  padding: 1rem;
  text-align: center;
}

nav {
  margin-top: 0.5rem;
}

nav a {
  color: white;
  text-decoration: none;
  margin: 0 10px;
  padding: 4px 8px;
  border-radius: 4px;
  transition: background 0.2s;
}

nav a:hover,
nav a.active {
  background-color: rgba(255, 255, 255, 0.2);
}

main {
  padding: 1.5rem;
  max-width: 700px;
  margin: 0 auto;
}

footer {
  text-align: center;
  background-color: #eee;
  padding: 0.8rem;
  margin-top: 2rem;
}