1)与其立即执行回调中的悬停项目的fadeIn，不如执行它.这样可以防止白色背景通过以下方式显示:

1) Rather than do the fadeIn of the hover item on the callback, do it immediately. This will prevent the white background showing through:

$('.grid-box .phase-1').fadeOut(300);
$('.grid-box .phase-2').fadeIn(300);

2)最简单的方法是在缩略图容器上指定大小，并在其上添加overflow: hidden;.

2) The easiest way to do this is to specify a size on the thumbnail container and the add overflow: hidden; to it.

3)最后，以下代码将确保仅将鼠标悬停在div内的元素受影响:

3) Finally the following code will make sure only the elements contained within the hovered-over div will be affected:

$(function(){
    $('.grid-box').hover(
        function(){
            $('.phase-1', this).fadeOut(300);
            $('.phase-2', this).fadeIn(300);
        },
        function(){
            $('.phase-2', this).fadeOut(300)
            $('.phase-1', this).fadeIn(300);
        }
    ); 
});