jQuery scrollTop跳到屏幕顶部

Question

When I load the page, the div is at the top of the screen, but when I start the scroll, it jumps to where it is supposed to be.

Check out the website here: calretirement.com/classes-test.php

CSS:

 .register{position:fixed !important; bottom:120px !important;   width: 340.453px;
  margin-top: 29px;
  }

  #stickyForm2015 {-webkit-transition: all 0.4s ease-in-out;
  -moz-transition: all 0.4s ease-in-out;
  transition: all 0.4s ease-in-out;
}

jQuery:

    <script>
    $(window).scroll(function(){
        if
      ($(window).scrollTop() > 670){
          $("#stickyForm2015").addClass("register");

        }


        else
        {
            $("#stickyForm2015").removeClass("register");
            updateSliderMargin();
        }


    });
</script>

<script>
    $(window).on("scroll", function(){
        if
      ($(window).scrollTop() > 2500){

            $("#stickyForm2015").removeClass("register");
            updateSliderMargin();
        }


    });
</script>

Open to suggestions!! Need help!

Answer 1

If you want to animate scroll with jquery you can just do:

$('html, body').animate({scrollTop: '0'}, 400);

If you want to animate with css you need to animate from something to something, your classes don't appear to be doing that.

.original-class{
    position: relative;
    top: 500px;
    transition: top .4s ease-in-out; //only necessary if you plan on animating back
}

.animate-original-class{
    top: 0;
    transition: top .4s ease-in-out;
}