Collection widget UI Resolution issue

Hi,

Please help me with below mentioned collection widget issues.

I created one base mashup to show on collection widget. On the base mashup i given some css style on container background like linear gradient effect by writing the css.

Now when i bind that base mashup to collection widget and view mashup on browser the css style is removed from the base mashup.

So for this i applied css on collection mashup and the css get applied successfully but only on single cell. When i add one more data or cell on the collection  then css for the second cell is get removed. To temporary solution on this i applied css style for individual cell but this is not the correct way.

I created the collection mashup with 100% resolution and after viewing the collection mashup on browser and tries to change resolution on browser the css get removed from the cells.