We couldn’t fully fit a filter in there yet, but we simplified the necessary CSS considerably:
@media (max-width: 1000px) {
.main-navigation .menu-toggle,
.main-navigation .mobile-bar-items,
.sidebar-nav-mobile:not(#sticky-placeholder) {
display: block;
}
.main-navigation ul,
.gen-sidebar-nav {
display: none;
}
[class*="nav-float-"] .site-header .inside-header > * {
float: none;
clear: both;
}
}
1000px being the width you want it to kick in at.