.modal{
  width: 100%;
  height: 100vh;
  background: rgba(0,0,0,0.9);

  position: absolute;
  top: 0;
  left: 0;

  display: flex;

  animation: modal 2s 0s forwards;
  visibility: hidden;
  opacity: 0;


}


.contenido{
  margin: auto;
  width: 40%;
  height:40%;
  background: white;
  border-radius: 10px;


}


#cerrar{
  display: none;


}


#cerrar + label{
  position: fixed;
  color: #fff;
  font-size: 25px;
  z-index: 50;
  background: darkred;
  height: 40px;
  width: 40px;
  line-height: 40px;
  border-radius: 50%;
  right: 46%;
  top: 30%;
  cursor:pointer;
  text-align: center;


  animation: modal 2s 0s forwards;
  visibility: hidden;
  opacity: 0;



}


#cerrar:checked + label, #cerrar:checked ~ .modal{
  display: none;
}

@keyframes modal {
  100%{
    visibility: visible;
    opacity: 1;

  }
}