div.cdmContentInner {position: relative; max-height: 200px; overflow-y: hidden }
div.cdmContentInner:after {display: block; position: absolute; left: 0; right: 0; top: 170px; height: 30px; background: linear-gradient(to bottom, rgba(255, 255, 255, 0), rgba(255, 255, 255, 0.
![Cool 8)](images/smilies/icon_cool.gif)
Basically it limits the content panel to 200px, and puts a pale blue gradient line at the bottom to indicate this.
You can change the height by changing the 200px part and the 170px part to match.