body {
      background: url('../img/fundo.jpeg') no-repeat center center fixed;
      background-size: cover;
    }
    .card {
      background: rgba(255, 255, 255, 0.85);
      border: none;
      border-radius: 1.5rem;
      box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
    }
    .card-body {
      padding: 2rem;
    }
    h4, h6 {
      color: #3a3a3a;
      font-weight: 700;
    }
    .form-label {
      color: #4e54c8;
      font-weight: 600;
    }
    .form-control {
      border-radius: 0.75rem;
      border: 1px solid #4e54c8;
      background: #f7f8fa;
      transition: border-color 0.2s;
    }
    .form-control:focus {
      border-color: #8f94fb;
      box-shadow: 0 0 0 0.2rem rgba(142, 148, 251, 0.25);
    }
    .btn-primary {
      background: linear-gradient(90deg, #4e54c8 0%, #8f94fb 100%);
      border: none;
      border-radius: 1rem;
      font-weight: 600;
      letter-spacing: 1px;
      box-shadow: 0 4px 16px rgba(142, 148, 251, 0.15);
      transition: background 0.2s;
    }
    .btn-primary:hover {
      background: linear-gradient(90deg, #8f94fb 0%, #4e54c8 100%);
    }
    #resultado {
      font-size: 1.2rem;
      color: #4e54c8;
      font-weight: 500;
      letter-spacing: 2px;
    }