gistfile1.txt

add_action( 'wp_head', function () { ?>
	<script>
		window.addEventListener( 'scroll', function() { 
			const limit = document.body.classList.contains( 'home' ) ? 300 : 50
			if ( ( window.pageYOffset || document.body.scrollTop ) > limit ) {
				if ( ! document.body.classList.contains( 'is-scrolling' ) ) {
					document.body.classList.add( 'is-scrolling' )
				}
			} else {
				if ( document.body.classList.contains( 'is-scrolling' ) ) {
					document.body.classList.remove( 'is-scrolling' )
				}
			}
		} )
	</script>
<?php } );