.folder li {
    display: inline-block;
    width: 22%;
    min-height: 80px;
    margin: 0 15px 15px 0;
    overflow: hidden;
    vertical-align: top;
}

    .folder li a {
        display: block;
        text-align: center;
        padding-top: 36px;
        background-position: center top;
        background-repeat: no-repeat;
    }