<div class="container">
<button id="btn" class="btn btn-primary">隱藏選單</button>
<form action="" class="mt-3">
<div class="form-row">
<div class="col-md-8">
<textarea rows="5" class="form-control"></textarea>
</div>
<div class="col-md-2 d-flex">
<div class="mt-auto">
<button type="submit" class="btn btn-danger h-10">傳送表單</button>
</div>
</div>
</div>
</form>
</div>
form{
opacity:0;
transition:all 1s;
}
form.active{
opacity:1;
}$(document).ready(function(e){
$('#btn').click(function(e){
$('form').toggleClass('active');
})
})