@media (max-width: 1100px) {
    #a_menu_mobile,
    #close_button
    {
        display: block;
        position: absolute;
        top: 18px;
        right: 18px;
        z-index: 4000;
    }

    #menu_shadow
    {
        transition: background-color .6s;
    }

    #menu_shadow.show
    {
        background-color: rgba(0,0,0,.4);
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: 2900;
    }

    #hamburger
    {
        margin-top: 5px;
        display: block;
        width: 30px;
        height: 30px;
        position: relative;
        -webkit-transform: rotate(0deg);
        -moz-transform: rotate(0deg);
        -o-transform: rotate(0deg);
        transform: rotate(0deg);
        -webkit-transition: .5s ease-in-out;
        -moz-transition: .5s ease-in-out;
        -o-transition: .5s ease-in-out;
        transition: .5s ease-in-out;
        cursor: pointer;
    }

    #hamburger span
    {
        display: block;
        position: absolute;
        height: 4px;
        width: 100%;
        background-color: #000000;
        border-radius: 2px;
        opacity: 1;
        left: 0;
        -webkit-transform: rotate(0deg);
        -moz-transform: rotate(0deg);
        -o-transform: rotate(0deg);
        transform: rotate(0deg);
        -webkit-transition: .25s ease-in-out;
        -moz-transition: .25s ease-in-out;
        -o-transition: .25s ease-in-out;
        transition: .25s ease-in-out;
    }

    #hamburger span:nth-child(1)
    {
        top: 0px;
    }

    #hamburger span:nth-child(2)
    {
        top: 10px;
    }

    #hamburger span:nth-child(3)
    {
        top: 20px;
    }

    #hamburger.open span:nth-child(1)
    {
        top: 12px;
        -webkit-transform: rotate(135deg);
        -moz-transform: rotate(135deg);
        -o-transform: rotate(135deg);
        transform: rotate(135deg);
    }

    #hamburger.open span:nth-child(2)
    {
        opacity: 0;
        left: -40px;
    }

    #hamburger.open span:nth-child(3)
    {
        top: 12px;
        -webkit-transform: rotate(-135deg);
        -moz-transform: rotate(-135deg);
        -o-transform: rotate(-135deg);
        transform: rotate(-135deg);
    }
}