/* MOBILE MENU sticky autohide */
@media only screen and (max-width: 1024px) {
/* For mobile: */
.header {
position: fixed;
top: 0; left: 0;
width: 100%;
transition: all .3s ease;
z-index: 9999999;
}
.header.out {
transform: translateY(-100%);
}
}/* end */
и добавить скрипт в хеад
add_action( 'wp_head', 'seomur_head' );
function seomur_head() {
?>
<script>
jQuery(document).ready(function($) {
var header = $('.header'),
scrollPrev = 0;
$(window).scroll(function() {
var scrolled = $(window).scrollTop();
if ( scrolled > 100 && scrolled > scrollPrev ) {
header.addClass('out');
} else {
header.removeClass('out');
}
scrollPrev = scrolled;
});
});
</script>
<?php
}

@seomur
Помощь и консультации по wordpress, woocommerce и ускорению сайта - https://t.me/seomur