@media screen and (max-width: 992px){
    #left-sidebar {
        left: -280px;
    }
    .page {
        left: 0;
        width: 100%;
    }
    .offcanvas-active #left-sidebar {
        left: 0;
        position: fixed;
        z-index: 99;
    }
    .offcanvas-active .page {
        left: 248px;
        width: 100%;
    }
    #main_nav {
        display: flex;
    }
    .navbar-nav.tree-menu {
        flex-direction: row;
    }
}

@media screen and (max-width: 768px){
    #main_nav {
        display: flex;
    }
    .navbar-nav.tree-menu {
        flex-direction: row;
    }
    .page-header .right .navbar-nav .dropdown-menu {
        position: absolute;
    }

}

@media screen and (max-width: 576px){
    .page-title {
        display: none;
    }
}