body {
    background: #f1f3f6;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  }
  
  .fade-in {
    animation: fadeIn 0.8s ease-in-out;
  }
  
  .navbar {
    background: linear-gradient(135deg, #0d6efd, #6610f2);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  }
  
  .navbar-brand,
  .nav-link {
    color: #fff !important;
    font-weight: 500;
  }
  
  .navbar-brand:hover {
    animation: pulse 1s infinite;
  }
  
  .nav-link:hover {
    color: #ffc107 !important;
    transition: 0.3s;
  }
  
  .nav-link.active {
    color: #ffc107 !important;
  }
  
  .form-section,
  .todo-section {
    background: #fff;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
    margin-top: 2rem;
    animation: slideInUp 0.7s ease-out;
  }
  
  .btn-outline-primary:hover {
    background-color: #0d6efd;
    color: white;
    transform: scale(1.05);
    transition: 0.3s ease-in-out;
  }
  
  .alert {
    margin-top: 1rem;
    border-left: 5px solid #0d6efd;
    animation: fadeIn 1s ease-in;
  }
  
  .form-control:focus {
    border-color: #0d6efd;
    box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.25);
    animation: glow 0.4s ease-in-out;
  }
  
  /* Animations */
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  @keyframes slideInUp {
    from {
      opacity: 0;
      transform: translateY(40px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  @keyframes glow {
    0% {
      box-shadow: 0 0 5px rgba(13, 110, 253, 0.3);
    }
    100% {
      box-shadow: 0 0 12px rgba(13, 110, 253, 0.6);
    }
  }
  
  @keyframes pulse {
    0% {
      transform: scale(1);
    }
    50% {
      transform: scale(1.1);
    }
    100% {
      transform: scale(1);
    }
  }