Utterly stumped. Trying to get rid of the active/focus box

Utterly stumped. Trying to get rid of the active/focus box shadows on .wp-core-ui .button-primary. The soft fuzz on the click state is driving me crazy as its horribly ugly and I'm desperate to get rid of it.

I've tried to mimic the existing WP CSS found in colors.css with no luck:

.wp-core-ui .button-primary:hover, .wp-core-ui .button-primary:focus {background: #c9c9c9 !important;color:#000000 !important; -webkit-box-shadow:0 0 0 #c9c9c9 inset, 0 0 0 rgba(0, 0, 0, 0.0) !important; box-shadow: 0 0 0 #c9c9c9 inset, 0 0 0 rgba(0, 0, 0, 0.0) !important;border:0 !important; }
.wp-core-ui .button-primary:active {border:0 !important;-webkit-box-shadow:inset 0 0 0 0 rgba(0, 0, 0, 0.0) !important; box-shadow: inset 0 0 0 0 rgba(0, 0, 0, 0.0) !important;}

VERY grateful for any advice...