#app-preloader {
    position: fixed;
    inset: 0;
    background: #f4f4f4;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
  }

  #preloader.hidden {
    opacity: 0;
    visibility: hidden;
  }

  .app-preloader-spinner {
    width: 60px;
    height: 60px;
    border: 6px solid #ccc;
    border-top-color: #007bff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
  }

  @keyframes spin {
    to {
      transform: rotate(360deg);
    }
  }