function animate(obj, target, callback) { // 盒子移动函数
    clearInterval(obj.timer);
    obj.timer = setInterval(move, 20);
    function move() {
        var step = (target - obj.offsetLeft) / 10;
        step = step > 0 ? Math.ceil(step) : Math.floor(step)
        obj.style.left = obj.offsetLeft + step + 'px';
        // obj.style.left = target + 'px'; // 闪变
        if (obj.offsetLeft == target) {
            clearInterval(obj.timer);
            if (callback) {
                callback();
            }
        }
    }
}

function animateY(obj, target, callback) { // 盒子移动函数
    clearInterval(obj.timer);
    obj.timer = setInterval(move, 10);
    function move() {
        var step = (target - window.pageYOffset) / 10;
        step = step > 0 ? Math.ceil(step) : Math.floor(step)
        // obj.style.left = target + 'px'; // 闪变
        if (window.pageYOffset == target) {
            clearInterval(obj.timer);
            callback && callback();
        }
        // window.pageYOffset = window.pageYOffset + step + 'px';
        window.scroll(0, window.pageYOffset + step)  // 不加单位
    }
}