#cell1 {
    grid-column:1/3;
    grid-row: 2/4
}

#cell2 {
    grid-column: 4/9;
    grid-row: 1/5
}

#cell3 {
    grid-column: 10/12;
    grid-row: 1/3
}

#cell4 {
    grid-column:11/16;
    grid-row: 4/8
}

#cell5 {
    grid-column: 2 /10;
    grid-row: 6 / 9
}


@media (max-width: 800px) {
    #cell1 {
        grid-column:1 / 5;
        grid-row: 1 / 4
    }

    #cell2 {
        grid-column: 6 / 16;
        grid-row: 1/7
    }

    #cell3 {
        grid-column: 1 / 5;
        grid-row: 5 / 7
    }

    #cell4 {
        grid-column: 1 / 16;
        grid-row: 8 / 9
    }

    #cell5 {
        grid-column: 1 /16;
        grid-row: 10 / 11
    }
}