Fusion Lite has 15 built in collapsing and automatically resizing module positions. For example, If you publish 3 modules in the top advert modules area, then all 3 will share the area equally (33% each module) wheras if you only have 1 module published in the top advert area then that module will fill the entire width (100%).

Publish nothing in the top advert area and the top advert module area will completely fall away.