gistfile1.txt

/* Modal */
.reports-modal{
    position: absolute;
    width: 80%;
    min-height: 400px;
    height: auto;
    z-index: 1900;
    background-color: #fff;
    padding: 0.75rem;
    border-top: 4px solid #1c5690;
    border-radius: 2px;
    box-shadow: 0 3px 10px 0 rgba(0, 0, 0, 0.3);
}

<div ng-class="{hidden:!data.reportModal}" class="bg-modal"></div>

<script>
    var modalReports = document.querySelector('.reports-modal');
    modalReports.style.left = ((window.innerWidth / 2) - (modalReports.offsetWidth / 2)) - ((window.innerWidth - document.documentElement.clientWidth) / 2) + 'px';


    console.log(modalReports.scrollTop);
</script>