body {
  font-family: Arial, sans-serif;
  background-size: cover;
  color: var(--text-color);
}

header {
  text-align: center;
  padding: 20px;
}

button {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 10px;
  cursor: pointer;
}