.mermer {
  background: #111;
}

.mermer-toggle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  min-width: 8rem;
  padding: 0.75rem 1.5rem;
  font: inherit;
  text-transform: uppercase;
  color: #fff;
  background: transparent;
  border: 1px solid #fff;
  cursor: pointer;
}

.mermer-toggle:hover {
  background: #fff;
  color: #000;
}