DRY

[maurusrv]

showPromotionBlack() {
    this.promotionPrompt.classList.remove("visibility-hidden");
    this.promotionPromptBlack.classList.remove("display-none");
  }

  hidePromotionBlack() {
    this.promotionPrompt.classList.add("visibility-hidden");
    this.promotionPromptBlack.classList.add("display-none");
  }

  showPromotionWhite() {
    this.promotionPrompt.classList.remove("visibility-hidden");
    this.promotionPromptWhite.classList.remove("display-none");
  }

  hidePromotionWhite() {
    this.promotionPrompt.classList.add("visibility-hidden");
    this.promotionPromptWhite.classList.add("display-none");
  }

let's practice dry principle by just creating one hidePromotion and one showPromotion and just pass black or white as a parameter