Croppie position issue

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://foliotek.github.io/Croppie/croppie.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.1/css/font-awesome.min.css">
<script src="http://foliotek.github.io/Croppie/croppie.js"></script>
<form action="test-image.php" id="form" method="post">
<input type="file" id="upload" value="Choose a file">
<div id="upload-demo"></div>
<input type="hidden" id="imagebase64" name="imagebase64">
<a href="#" class="upload-result">Send</a>
</form>

JavaScript

$( document ).ready(function() {
    var $uploadCrop;

    function readFile(input) {
        if (input.files && input.files[0]) {
            var reader = new FileReader();          
            reader.onload = function (e) {
                $uploadCrop.croppie('bind', {
                    url: e.target.result
                });
                $('.upload-demo').addClass('ready');
            }           
            reader.readAsDataURL(input.files[0]);
        }
    }

    $uploadCrop = $('#upload-demo').croppie({
        viewport: {
            width: 200,
            height: 200,
            type: 'circle'
        },
        boundary: {
            width: 300,
            height: 300
        }
    });

    $('#upload').on('change', function () { readFile(this); });
    $('.upload-result').on('click', function (ev) {
        $uploadCrop.croppie('result', {
            type: 'canvas',
            size: 'original'
        }).then(function (resp) {
            $('#imagebase64').val(resp);
            $('#form').submit();
        });
    });

});