.block-subnav {
    position:relative;
    width:100%;
    height: 32px;
}
.block-subnav.stuck .subnav-wrap {
    position:fixed;
    top:0;
    left:0;
    z-index:99;
    width:100%;
    box-shadow:0 0 3px rgba(0,0,0,.3);
}
.block-subnav .subnav-wrap .nav .nav-item:not(:last-of-type) {
    border-right: 1px solid rgba(255,255,255,.2);
}
.wp-admin .block-subnav {
    position:relative !important;
    overflow:hidden;
    max-height: 30px;
}
.wp-admin .block-subnav a {
    pointer-events: none;
}

.admin-bar .block-subnav.stuck .subnav-wrap {
    top: 32px;
}