body {
  background-color: #121212;
  color: #f5f5f5;
  font-family: 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
}

header {
  background-color: #1e1e2e;
  padding: 20px;
  text-align: center;
}

nav a {
  color: #f5f5f5;
  margin: 0 10px;
  text-decoration: none;
}

.category {
  margin: 20px;
  padding: 10px;
  background-color: #2a2a3d;
  border-radius: 8px;
}