Create children counter

counter.css

.counter-container {
    counter-reset: number-counter;
}
.counter-container > div:before {
    color: #666;
    content: counter(number-counter, decimal);
    counter-increment: number-counter;
    display: inline-block;
    float: left;
    height: 30px;
    line-height: 30px;
    margin: 7px 5px 0;
    width: 30px;
}