Div with fixed position in a scrollable modal

Question

I have a div in a modal with scroll that should have fixed position relative to the browser window, and should not scroll away with the modal.

I tried position:fixed, but it doesn't work. Here you can see issue in it's context:

$('.launchConfirm').on('click', function (e) {
    $('#confirm').modal({
        show: true
    });
});

@import url( 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css' );

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
<div class="page-container">
    <div class="container">
        <br />
        <button type="button" class="btn launchConfirm">Open modal</button>
    </div>
</div>
<div class="modal fade" id="confirm">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                </button>
                 <h4 class="modal-title">Modal title</h4>

            </div>
            <div class="modal-body">
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <div style="position:fixed;top:40px;left:10px;background-color:red">This div should be fixed<br>and should not scroll away.</div>
            </div>
            <div class="modal-footer">
                some random buttons
            </div>
        </div>
        <!-- /.modal-content -->
    </div>
    <!-- /.modal-dialog -->
</div>
<!-- /.modal -->

How could I fix that div?

Answer 1

You will need to move the DIV outside of the modal.

Fixed positioning works in relation to the viewport except when an ancestor element has a transform applied to it. .modal-dialog has transform applied to it which creates a new context in which to position the DIV (this is why your DIV stays inside of the modal).

CSS Positioning - MDN

Answer 2

You can use like this.

$('.launchConfirm').on('click', function (e) {
    $('#confirm').modal({
        show: true
    });
});

@import url( 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css' );
.modal-open .modal {
   overflow: hidden;
 }
 .modal-body {
   height: calc(100vh - 126px);
   overflow-y:scroll;
 }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
<div class="page-container">
    <div class="container">
        <br />
        <button type="button" class="btn launchConfirm">Open modal</button>
    </div>
</div>
<div class="modal fade" id="confirm">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span>
                </button>
                 <h4 class="modal-title">Modal title</h4>

            </div>
            <div class="modal-body">
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <p>One fine body&hellip;</p>
                <div style="position:fixed;top:40px;left:10px;background-color:red">This div should be fixed<br>and should not scroll away.</div>
            </div>
            <div class="modal-footer">
                some random buttons
            </div>
        </div>
        <!-- /.modal-content -->
    </div>
    <!-- /.modal-dialog -->
</div>
<!-- /.modal -->