Create an original square green promotion poster with a centered horizontal coupon, large “45% OFF”, bold English copy, dots, and a simple button. Text: “BIG PROMOTION”, “45% OFF”, “ONLY 3 DAYS”, “DON'T MISS THE CHANCE”, “SHOP NOW”. Keep the light green, yellow, and white palette. Use two small rays only; no ribbons or confetti. No logo, watermark, QR code, website, non-English text, or random tiny text.