How to remove borders and shadowing from Button Checkboxes widget?

PS.  I also have borders and shadowing... I just can't remove them.

Also, I've asked before but not received an answer, is there a way to change the styling of my blue button in one CSS file rather than one by one?

Please add the following CSS code to each widget to remove borders and shadowing:

.wrapperButtonCheckbox {

    border: none;

    box-shadow: none;

}