consul/ui/packages/consul-ui/app/styles/components/secret-button.scss

@import './secret-button/index';
.type-reveal {
  @extend %secret-button;
}
%secret-button {
  position: relative;
}
%secret-button span {
  visibility: hidden;
  position: absolute;
}
%secret-button em {
  margin-left: 22px;
}
%secret-button span::before {
  @extend %with-visibility-show-mask, %as-pseudo;
  background-color: $gray-500;
}
%secret-button input:checked + span::before {
  @extend %with-visibility-hide-mask;
}