.overlay {
    position: fixed;
    top:0px;
    left:0px;
    right:0px;
    bottom:0px;
    background-color: rgba(0,0,0,0.5);
    display:flex;
    align-items:center;
    justify-content: center;
}

.mensaje {
    padding: 20px;
    border-radius: 10px;
    background-color: #fbfc88;
    border: 3px solid darkslategray;
    color:black;
}