body {
    background-color: #f8f9fa;
    font-family: 'Arial', sans-serif;
  }
  
  .navbar-brand {
    font-size: 1.5rem;
  }
  
  #stockChart {
    max-width: 100%;
    height: 400px;
  }
  
  .modal-header, .btn-primary, .btn-success {
    background-color: #343a40;
    color: #fff;
  }
  
  .btn-primary, .btn-success {
    border: none;
  }
  
  .modal-content {
    border-radius: 10px;
  }
  
  .form-control {
    border-radius: 5px;
  }
  
  .modal-header .close {
    color: #fff;
    opacity: 1;
  }
  
  .modal-header .close:hover {
    color: #ff6b6b;
  }
  
  .form-group label {
    font-weight: bold;
  }
  
  .btn-primary:hover, .btn-success:hover {
    background-color: #495057;
  }