JS - 判断鼠标指针移动离开页面

    function initMouseout() {
        document.body.addEventListener('mouseout', (evt) => {
            if (!evt) var evt = window.event;
            var to = evt.relatedTarget || evt.toElement;
            if (!to || to.nodeName == "HTML") {
                $('#menu_hover_bg')
                    .stop()
                    .animate({
                        height: '0'
                    }, 100);
            }
        });
    }

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