Stackoverflow - Fixed div inside the container

HTML

<script src="code.jquery.com/jquery-2.2.4.min.js"></script>
<div class="wrapper">
    <div class="container">
        <div class="element">
            fixed
        </div>
    </div>
</div>

CSS

.wrapper {
    width:100%
}
.container {
    width:300px;
    margin:0 auto;
    height:900px;
    background:#ccc;
}
.element {
    background:#f2f2f2;
    position:fixed;
    width:50px;
    height:70px;
    top:50px;
    right:0px;
    border:1px solid #d6d6d6;
}

JavaScript

$(document).ready(function(){
fixedFunction();
});
$(window).resize(function(){
fixedFunction();
});

function fixedFunction(){
var containerWidth = $(".container").outerWidth();
var elementWidth = $(".element").outerWidth();
var containerOffsetLeft = $(".container").offset().left;
var containerOffsetRight = containerOffsetLeft + containerWidth - elementWidth;
	$(".element").css("left", containerOffsetRight);
}