#loader-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(128,128,128,0.2);
    z-index: 9999;
  }

  #loader {
    border: 16px solid #f3f3f3;
    border-top: 16px solid #3498db;
    border-radius: 50%;
    width: 80px;
    height: 80px;
    margin: 15% auto;
    animation: spin 1s linear infinite;
  }

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