#menue_mobile {
    display: none;
    width: 900px;
    overflow: hidden;
    z-index: 1000;
}

nav {
    float: left;
    background: #3a3a3a;
    background: blue;
    font-size: 16px;
    width: 200px;
    height: 100%;
    top: 0;
    bottom: 0;
    background: transparent;
    min-width: 1000px;
    top: 0;
    bottom: 0;
    max-height: 800px;
    overflow-x: auto;
    scrollbar-track-color: transparent;
}

    nav ul {
        width: 200px;
        background: blue;
        margin: 0;
        padding: 0;
        overflow:visible;
    }

    nav a {
        display: block;
        color: #fff;
        text-decoration: none;
    }

    nav ul li {
        position: relative;
        background: blue;
        float: left;
        width: 200px;
        list-style: none;
        color: #fff;
        transition: 0.5s;
    }

    nav ul li a {
        padding: 20px;
    }

    nav ul > li.submenu > a:after {
        position: relative;
        float: right;
        content: '';
/*        margin-left: 10px;
        margin-left: auto;
*/      
        margin-right: -10px;
        right: -10px;

/*        margin-top: 5px;
        border-left: 5px solid transparent;
        border-right: 5px solid transparent;
        border-top: 5px solid #fff;
        border-bottom: 5px solid transparent;
*/
        border-left: 5px solid #fff;
        border-right: 5px solid transparent;
        border-top: 5px solid transparent;
        border-bottom: 5px solid transparent;

    }

    nav ul ul li.submenu > a:after {
        margin-left: auto;
        margin-right: -10px;
        border-left: 5px solid #fff;
        border-right: 5px solid transparent;
        border-top: 5px solid transparent;
        border-bottom: 5px solid transparent;
    }

    nav ul li:hover {
        background: #4096ee;
        background: blue;

    }

    nav ul ul {
        position: absolute;
        top: -9999px;
        left: -9999px;
        /*background: #333;*/
        background: blue;
        box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.5);
        z-index: 9999;
    }

    nav ul ul li {
        position: relative;
        float: none;
        top: -60px;
        width: 200px;
        border-bottom: 1px solid #555;
        background: blue;
    }

        nav ul ul li a {
            padding: 10px 20px;
        }

        nav ul ul li:last-child {
            border-bottom: none;
        }

    nav ul li:hover > ul {
        position: absolute;
        top: 0;
        background: transparent;
        left: 0;
        left: 200px;
        width: 700px;
        height: 500px;
        overflow-x: scroll;
        scrollbar-track-color: transparent;
        scrollbar-track-color: red;
    }

    nav ul ul li:hover > ul {
        top: 0;
        left: 200px;
        background: blue;
    }

    nav ul li a:hover {
        background: blue;
    }