#save_button:disabled,
#submit_button:disabled {
  background-color: #ccc;
  color: #666;
  cursor: not-allowed;
  opacity: 0.6;
}

.loader {
  border: 16px solid #f3f3f3; /* Light grey */
  border-top: 16px solid #3498db; /* Blue */
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 2s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}