.promo-diagonal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-45%, -50%) rotate(-45deg);
  font-size: clamp(30px, 6vw, 70px); /* responsywny rozmiar */
  font-weight: bold;
  color: white;
  background: rgba(255, 0, 0, 0.50);
	border: 2px solid rgba(255, 0, 0);
  padding: 1em 2em;
  z-index: 9999;
  white-space: nowrap;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(0,0,0,0.3);
  transition: background 0.3s ease, transform 0.3s ease;
}

.promo-diagonal:hover {
  background: rgba(200, 0, 0, 0.95);
  transform: translate(-50%, -50%) rotate(-45deg) scale(1.05);
	border: none;
}