.hex {
    float: left;
    margin-left: 1px;
    margin-bottom: -1px;
}
.hex .top {
    width: 0;
    border-bottom: 2px solid #efefef;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
}
.hex .middle {
    width: 8px;
    height: 4px;
    background: #efefef;
}
.hex .bottom {
    width: 0;
    border-top: 2px solid #efefef;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
}
.hex-row {
    clear: left;
}
.hex-row.even {
    margin-left: 5px;
}

.hex.alive .top  {
    border-bottom: 2px solid #888;
}

.hex.alive .middle {
    background: #888;
}

.hex.alive .bottom {
    border-top: 2px solid #888;
}

#world {
    text-align: center;
    margin: 10px auto;
    width: 1180px;
}