JSFiddle - React, Tailwind, and code Playground
HTML
<form name="" method="post" action="" onsubmit="">
<div style="padding-bottom:10px; ">
<select >
<option value="3">Вы новый пользователь?</option>
<option value="1">Я новый пользователь</option>
<option value="2">У меня уже есть кабинет</option>
</select>
</div>
<div id="my1" class="form_row" ><input type="text" placeholder="значение 1"></input></div>
<div id="my2" class="form_row" ><input type="text" placeholder="значение 2"></input></div>
<div id="my3" class="form_row" ><input type="text" placeholder="значение 3"></input></div>
<div id="my4" class="form_row" ><input type="text" placeholder="значение 4"></input></div>
<div id="my5" class="form_row" ><input type="text" placeholder="значение 5"></input></div>
<div id="my6" class="form_row btn_row" ><input name="submit" id="submit" value="Принять" type="submit"></div>
</form>
CSS
.form_row{
padding-bottom:10px;
display:none;
}
.btn_row{
display:none;
padding-bottom:6px;
margin-top:14px;
}
JavaScript
$("select").on("change",function(){
$elem = $(this)
$val = $elem.val();
$rows = $(".form_row");
$visible = $rows.filter(':visible');
$time = 300;
if($val == "1"){
if($visible.length>0){
$visible.fadeOut($time ,function(){
$rows.show($time);
});
}else{
$rows.show($time);
}
}else if($val == "2"){
if($visible.length>0){
$visible.fadeOut($time ,function(){
$("#my, #my3").show($time);
});
}else{
$("#my, #my3").show($time);
}
$('input[name="other"]').attr('value','');
}else if($val == "3"){
$visible.fadeOut($time);
}
})