.spinner {
    position: absolute;   /* Position relative to the button */
    top: 50%;             /* Vertically center it */
    left: 50%;            /* Horizontally center it */
    transform: translate(-50%, -50%); /* Ensure it's perfectly centered */
    border: 3px solid #f3f3f3; /* Light grey background */
    border-top: 3px solid #fff; /* White spinner */
    border-radius: 50%;
    width: 20px;
    height: 20px;
    animation: spin 1.5s linear infinite;
  }
  
  @keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
  }