body.vertical-layout.vertical-menu.menu-expanded .main-menu .navigation li.has-sub > a:not(.mm-next):after{
    content: "\e90f"!important;
        font-family: feather !important;
}

body.vertical-layout.vertical-menu.menu-expanded .main-menu .navigation li.open > a:not(.mm-next):after{
    -webkit-transform: rotate(90deg)!important;
    -moz-transform: rotate(90deg)!important;
    -ms-transform: rotate(90deg)!important;
    -o-transform: rotate(90deg)!important;
    transform: rotate(90deg)!important;
}