.c-overlay[aria-hidden] {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: var(--overlay-z-index);
  display: block;
  width: 100%;
  height: 100%;
  background-color: transparentize(#000, 0.6);
  visibility: hidden;
  opacity: 0;

  &.c-overlay--visible {
    visibility: visible;
    opacity: 1;
  }

  &.c-overlay--transparent {
    background-color: transparent;
  }
}