`<div id='loadingScreen'>` has a width of 0 because of the `position:absolute` and the positioning isn't working because of it. Adding a width of 100% to `<div id='loadingScreen'>` doesn't solve the problem.

CSS: 

```
        #loadingScreen{
            position:relative;
        }
        .centered{
            height:100px;
            position:absolute;
            top:50%;
            margin-top:-50px;
        }

```

HTML:

```
    <div id="loadingScreen">
        <div class="centered">
            <!--stuff-->
        </div>
    </div>

```