nav {
  background: linear-gradient(to bottom, #0057b8 50%, #ffd700 50%);
}

#command-hint {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 60px;
  font-weight: bold;
  color: white;
  display: none;
  opacity: 0;
  padding: 20px 40px;
  border-radius: 12px;
  text-align: center;
  transition: opacity 1s ease;
  z-index: 9999;
  background: rgba(0,0,0,0.6);
}