.portfo {

    background-color: gray;
    columns: 3;
    padding: 2%;
    text-align: center;
   
}

.portfo img {
    display: block;
    margin-left: auto;
    margin-right: auto;
}



@media screen and (max-width: 880px) {  

    .portfo {
        font-size: 10px;
    }

}



@media screen and (max-width: 585px) {  

    .portfo {
        columns: 1;
    }

    section ul li {
        font-size: 13px;
    }

}