At 641-767px the sidebar was in a no-mans-land: hamburger hidden (<=640 only)
and rail also hidden (>=768 only). Users could still navigate via the sidebar-nav
tabs inside the sidebar, but the rail was absent unnecessarily.
Changing the rail breakpoint from min-width:768px to min-width:641px closes the
gap. The sidebar slide-in behavior (position:fixed, hamburger toggle) stays at
<=640px only, so the mobile UX is unchanged. At 641-767px the rail now appears
alongside the persistent sidebar.
Co-authored-by: nesquena-hermes <nesquena-hermes@users.noreply.github.com>
533edbcae0
