body {
    text-align: center;
    font-family: sans-serif;
    margin: 0;

}

.modal {
    width:100%;
    height:120vh;
    z-index: 10;
    background: rgba(0,0,0,0.8);
    position: absolute;
    top: 0;
    left: 0;
    display: flex;
    animation: modal 2s 3s forwards;
   
    visibility: hidden;
    opacity:0;
}
.contenido {
    margin: auto;
    width: 40%;
    height: 50%;
    background: white;
    border-radius: 10px;    


}
#cerrar {
    display: none;

}
#cerrar + label {
    position: fixed;
    color: #fff;
    font-size: 25px;
    z-index: 100;
    background: darkred;
    height: 40px;
    width: 40px;
    line-height: 40px;
    border-radius: 50%;
    right: 10px;
    cursor:pointer;
    animation: modal 2s 3s forwards;
    visibility: hidden;
    opacity:0;
}

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

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

}