* {
    margin: 0;
    padding: 0;
  }
  
  .top-bar {
    background: #333;
    color: #fff;
    padding: 1rem;
  }
  
  .btn {
    background: coral;
    color: #fff;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 0.7rem 2rem;
  }
  
  .btn:hover {
    opacity: 0.9;
  }
  
  .page-info {
    margin-left: 1rem;
  }
  
  .error {
    background: orangered;
    color: #fff;
    padding: 1rem;
  }

  canvas {
    margin: 50px auto;
  }