body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f6f8fa;
  color: #222;
}
header {
  background: #2d3e50;
  color: #fff;
  padding: 2rem 1rem;
  text-align: center;
}
nav {
  display: flex;
  justify-content: center;
  background: #1a2533;
}
nav a {
  color: #fff;
  padding: 1rem;
  text-decoration: none;
  transition: background 0.2s;
}
nav a:hover {
  background: #3d5a80;
}
section {
  max-width: 700px;
  margin: 2rem auto;
  background: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
footer {
  text-align: center;
  padding: 1rem;
  background: #2d3e50;
  color: #fff;
  position: fixed;
  width: 100%;
  bottom: 0;
}