Following 2 files need to be updated...
1) templates/tmpl_uni/css/general.css
2) orca/layout/uni/css/uni.css
For each of the above 2 files, you need to change "height" parameter under the "topBlock" tag. See the sample below:
.topBlock
{
position:relative;
height:100px;
border:0px dashed blue;
margin-bottom:0px;
}