.modal {
  display: none;
  position: fixed;
  z-index: 999;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0,0,0,0.4);
}

/* Contenido del modal */
.modal-contenido {
  background-color: #fff;
  margin: 10% auto;
  padding: 20px;
  border-radius: 6px;
  width: 60%;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
}

/* Botón de cerrar */
.cerrar {
  color: #aaa;
  float: right;
  font-size: 24px;
  font-weight: bold;
  cursor: pointer;
}

.cerrar:hover {
  color: black;
}

@media (max-width: 576px) {
  form.form-inline label,
  form.form-inline input,
  form.form-inline button {
    width: auto;
    flex: 1 1 auto;
  }
  form.form-inline input {
    min-width: 0;
  }
}