After reviewing the code snippet you shared, it appears to be functioning correctly. However, if you are facing any issues, I recommend checking the CSS for potential problems. Alternatively, here are some other methods you can try: you could utilize fadeIn() and fadeOut(), hide() and show(), manipulate css visibility or display properties, or explore the jquery UI animate functionality. For a demonstration of animation to hide a div, you can refer to this example on jquery animate
$(window).scroll(function() {
var top_of_element = $("#element").offset().top;
var bottom_of_element = $("#element").offset().top + $("#element").outerHeight();
var bottom_of_screen = $(window).scrollTop() + $(window).innerHeight();
var top_of_screen = $(window).scrollTop();
if ((bottom_of_screen > top_of_element) && (top_of_screen < bottom_of_element)){
// the element is visible, take action
} else {
// the element is not visible, perform alternate action
}
});
$(window).scroll(function() {
var tint = $('.register').offset().top;
if ($(this).scrollTop() > tint) {
$('.register').fadeIn();
// OR
//$(".register").show();
// OR
//$(".register").css('visibility', 'visible');
} else {
$('.register').fadeOut();
// OR
//$(".register").hide();
// OR
//$(".register").css('visibility', 'hidden');
}
});
.tint {
background-color: #000;
width: 100%;
height: 100vh;
opacity: 0.6;
position: absolute;
top: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<section class="register">
<div class="tint"></div>
<div>Content</div>
</section>