#tutorial{

    margin-left: auto;

    margin-right: auto;



}

.grid {
    width: 1024px;
    height: 1024px;
    font-size: 1rem;
}
.row {
    display: flex;
}
.box {
    background: rgb(220, 0, 0);
    width: 20px;
    height: 20px;
    margin: 0px;
    color: white;
    flex: 1 0 auto;
    position: relative;
}
.box:after {
    content: "";
    float:left;
    display: block;
    padding-top: 100%;
}
.box .inner {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    top: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

#id{
    background: blue;
}