html { position: relative; min-height: 100%; }
body { margin: 0; } /* reset margins */

.footer {
    background-color: #353535;
    padding: 15px 0;        /* use padding, not fixed height */
}

#contentFooter {
    margin: 0;
    width: 100%;
    background: #353535;
    color: #939fa6;
}