<div class="container">
<a href="#" class="btn btn-primary">隱藏區塊</a>
<div class="box mt-5 bg-dark">
</div>
</div>.box{
width: 300px;
height: 300px;
}
$(document).ready(function(){
$('a').click(function(e){
$('.box').slideUp(1000).slideDown(1000);
})
})