slide down of jQuery in WordPress not works correctly

Question

I want to slide down some Divs in WordPress using jQuery slide down. but all item come over each other. here is my code:

$(".more-button").click(function(){
  $("#feature-column").slideDown();
  slideFadeOut($('.more-button'));
});

$(".less-button").click(function(){
  $( "#feature-column" ).slideUp(2000);
  slideFadeIn($('.more-button'));
}); 
})

and div is some thing like this:

<div class="more-button"> show more </div>
    <div id="feature-column">
    <div>123</div>
    <div>123</div>
<div class="less-button"> show less</div>

    </div>

image of wrong slide down

image of correct slide down