message: Darken button outline
diff: @@ -161,8 +161,8 @@ const Button = styled(_Button)<ButtonProps & { styledSize: any }>`
  &:focus {
  outline: unset;
  z-index: 2;
  - box-shadow: ${props => palette(props.palette === 'default' ? 'primary300' : `${props.palette}300`)(props)} 0px 0px
  - 0px 2px;
  + box-shadow: ${props => palette(props.palette === 'default' ? 'primary' : `${props.palette}300`)(props)} 0px 0px 0px
  + 2px;
  }
  &[disabled] {
  