body{
    text-align: center;
    font-family: sans-serif;
    margin: 0;
}
.modal {
    width: 100%;
    height: 100vh;
    
      /*background: red rgba(0,0,0,0.8);*/
    background: transparent;
    position: absolute;
    top: 180px;
    left: 0;
    display: flex;
    animation:  modal 7s 9s forwards;
    visibility: hidden;
    opacity: 0;
}
.contenido {
   
    width: 80%;
    margin-left: auto;
    margin-right: auto;
    height: auto;
    padding: 20px;
    background: #cdd0d3;
       color: black;
    border-radius: 10px;
}
#cerrar {
    display: none;
}
#cerrar + label {
    position: fixed;
    color: #fff;
    font-size: 25px;
    z-index: 50;
    background: red;
    height: 40px;
    width: 50px;
    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;
    }
}