.modal2 {

    background: rgba(0,0,0,0.8);
    
    position: fixed;
    
    display: flex;
    
    animation: modal 2s 3s forwards;
    visibility: hidden;
    opacity: 0;
    z-index: 2;
    width: 100%;
    height: 100%;
    overflow: auto;
}

.contenido {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 650px;
}

#cerrar2 {
    display: none;
}

#cerrar2 + label {
    position: fixed;
    color: #fff;
    font-size: 50px;
    z-index: 3;
    background: darkred;
    height: 40px;
    width: 40px;
    line-height: 40px;
    border-radius: 50%;
    right: 35px;
    top: 15px;
    cursor: pointer;
    
    animation: modal 2s 3s forwards;
    visibility: hidden;
    opacity: 0;
}

#cerrar2:checked + label, #cerrar2:checked ~ .modal2 {
    display: none;
}

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