#art {
    display: table;
    border-spacing: 1px;
    background-color: black;
    border: 5px solid black;
}
.row {
    display: table-row;
}

.pixel {
    display: table-cell;
    background-color: white;
    width: 40px;
    height: 40px;
}

.pen{
    display:inline-block;
    width:40px;
    height:40px;
    border:2px solid black;
}