Hey there,
Do you mean that you want to fill up the spaces which is on the red line that you drew on the screenshot?
If yes, I had added the following CSS code for it at
Backend > EasySocial > Themes > Custom CSS:
/*Fill the spaces on the left and right on screen*/
#es.es-mobile-wrapper .es-stream {
padding: 8px 0px 0;
}
Can you have a look and see how it goes?