.blurBG {
    /* z-index: 20; */
    position: absolute;
    top: 0;
    left:-5px;
    width: 100%;
    height: 100%;
      background-color: rgba(0,0,0,0.4);
  }
  .blurBG-content {
    position: absolute;
    border: 16px solid #f3f3f3; /* Light grey */
    border-top: 16px solid #3498db; /* Blue */
    border-radius: 50%;
    width: 50px;
    height: 50px;
    top: 40%;
    left:50%;
    animation: spin 2s linear infinite;
    }
    
    @keyframes spin {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }

    .div_hidden {
        display: none;
    }
    .div_visible {
        display: block;
    }