根据更新后的代码，您在#switch的空白处设置了200px的空白；

Per your updated code, you are setting the "left" of the #switch when you gave it a margin of 200px;

更改

$('#switch').animate({"left": 5});
$('#switch').animate({"left": 200});

到

$('#switch').animate({"margin-left": 5});
$('#switch').animate({"margin-left": 200});