#life {
    width: 510px;
    height: 510px;
    position: relative;
    margin: 100px auto 0;
}

.cell {
    width: 10px;
    height: 10px;
    background: #FFF;
    float: left;
    /*border: 1px solid red;*/
}


/* extra */
.x, .y {
    font-size: 10px;
    position: absolute;
    font-family: monospace;
}

.x {
    top: -15px;
}

.x span {
    display: inline-block;
}

.x span:nth-child(2n) {
    position: relative;
    top: -10px;
}

.y {
    text-align: right;
    left: -15px;
    line-height: 12.5px;
}


.y span {
    display: block;
}