body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, sans-serif;
  background-color: #f9fafb;
  color: #111827;
}
header {
  background-color: #111827;
  color: white;
  text-align: center;
  padding: 30px 20px;
}
nav {
  background-color: #1f2937;
}
nav ul {
  list-style: none;
  margin: 0;
  padding: 10px 20px;
  display: flex;
  gap: 20px;
}
nav a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 500;
}
nav a:hover {
  text-decoration: underline;
}
main {
  max-width: 960px;
  margin: 30px auto;
  padding: 0 20px;
}
footer {
  background: #e5e7eb;
  text-align: center;
  padding: 20px;
  font-size: 0.9rem;
  color: #374151;
  margin-top: 40px;
}