.wp-core-ui .button-primary {
background: #3aa1b8;
border-color: #3aa1b8 #266a79 #266a79;
-webkit-box-shadow: 0 1px 0 #266a79;
box-shadow: 0 1px 0 #266a79;
color: #fff;
text-decoration: none;
text-shadow: 0 -1px 1px #266a79, 1px 0 1px #266a79, 0 1px 1px #266a79, -1px 0 1px #266a79;
} 

.wp-core-ui .button-primary.focus, .wp-core-ui .button-primary.hover, .wp-core-ui .button-primary:focus, .wp-core-ui .button-primary:hover {
background: #266a79;
border-color: #266a79;
color: #fff;
}

.wp-core-ui .button-primary.active, .wp-core-ui .button-primary.active:focus, .wp-core-ui .button-primary.active:hover, .wp-core-ui .button-primary:active {
-webkit-box-shadow: inset 0 2px 0 #266a79;
box-shadow: inset 0 2px 0 #266a79;
}