Apply nav-tabs overflow rules only to small screens

Problem/Motivation

We need to apply this rules only for small screens and not bigger screens for now because when `overflow-y: hidden` is applied active tab will not be able to cover nav-tabs bottom border so we will get a small visual bug.
This is not easy to fix. One way, to avoid overflow problem, is to use `nav-tabs::before` absolute pseudo-element, but this is complicating then the z-index situation with li.nav-item because we do not have nav-item--active CSS class for now to target only active tab.
So for now limiting this overflow rules to small screens limits this bug to small screens only.