( function() {
'use strict';
// Check if the browser supports querySelector and addEventListener
if ( 'querySelector' in document && 'addEventListener' in window ) {
// Get the body element
var body = document.body;
// Add event listener for pointer interactions with passive option
body.addEventListener( 'pointerdown', function() {
body.classList.add( 'using-mouse' );
}, { passive: true } );
// Add event listener for keyboard interactions
body.addEventListener( 'keydown', function() {
body.classList.remove( 'using-mouse' );
}, { passive: true } );
}
}() );