I'm learning css and decided to understand something in Facebook: the minifeed on the right, allows scrolling without using frames. How does it work?

I suspect I may know the answer by now, but I can't find a definite proof. It's a smaller fixed element, containing a larger element. Then the relative position of the inner larger element relative to the outer smaller one, is being changed by js in response to mouse events. All this is ok. Now the problem: 

I can't find where this relative position is defined. I'm using Chromes "inspect element" and trying to spot the place where this positioning is defined, and thus probably changed by js. 

I found that :

```
<div class="tickerActivityStories" ...

```

is the inner large element, and that:

```
<div class="uiScrollableAreaWrap ...

```

is the first ancestor that is smaller, and thus limiting it to a "virtual frame".

But I cannot find where the position of the first relative to the last, is set. I'm going through the styles and the computed styles that chrome shows me, and can't see any relevant positioning directive. The following types of help will be appreciated:

* A specific answer to this specific matter by somebody who opened facebook and checked.
* A guidance about what I may have been doing wrong to find the answer, and how could I do it better