SOURCE

<div></div>

div {
    display: inline-block;
    /* padding: 100px; */
    width: 100px;
    padding: 0;
    padding-top: 100%;
    background-color: #fff;
    background-image: linear-gradient(45deg, #eee 25%, transparent 25%, transparent 75%, #eee 75%), linear-gradient(45deg, #eee 25%, transparent 25%, transparent 75%, #eee 75%);
    background-size: 16px 16px;
    background-position: 0 0, 8px 8px;
}