Maika provide 7 options setting , they are Layout, Gallery, Filter & Order, Pagination, Skin & Animation, Font & Color, Custom CSS.
At here, you need choose layout for shortcode
At this tab, you can create catetory or sub-category by right click at 'Category tree', and click 'Add image' at right section to add image to category
With setting, you can change gallery title font size, category title font size, font color and hover color
Using this feature, you can add your style sheet for gallery: