.slider-menu {
    overflow: hidden;
}

    .slider-menu .slider {
        width: 200%;
    }

    .slider-menu ul {
        display: inline-block;
        width: 50%;
        vertical-align: top;
    }

        .slider-menu ul li:not(.back) a::after {
            content: "\f105";
            font-family: FontAwesome;
            position: absolute;
            right: 10px;
        }

        .slider-menu ul li.back a:before {
            content: "\f104";
            font-family: FontAwesome;
            position: absolute;
            left: 10px;
        }