Button margin and size on tiddler view toolbar: extra spaces between buttons, how to adjust

[Mohammad]

In Trashbin plugin I have added buttons to tiddler view toolbar! It seems these new butons does not follow the style by TW

and cause extra spaces (seems margin or padding). How can I adjust these spaces and create buttons look the same as original TW

You can see the below images or directly examine them at https://kookma.github.io/TW-Trashbin/

--Mohammad