How to make admin panel backend FULL Width

my admin panel is smaller than my screen
need to make it wider or full width

any help appreciated!

At first it is required to add an ability to specify your CSS for admin panel

Then try to use the following code

#main_column {
    .navbar-admin-top, .admin-content-wrap, .content-wrap {
        max-width: none !important;
    }
}

(!) Not tested