.calculadora-container {
  background: #fff;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.form-group {
  margin-bottom: 15px;
}
.btn-primary {
  background-color: #0073aa;
  color: #fff;
  border: none;
  padding: 10px;
  border-radius: 5px;
  cursor: pointer;
}