Birthday greeting poster design. A gradient background transitioning from deep blue to bright yellow. At the bottom center, a lit candle with pop-art polka dots, with flames erupting upward into extremely vibrant and colorful letters. The letters feature a hand-drawn doodle style with dry brush texture, in red, blue, yellow, and green, radiating outward in an explosive burst. In the upper center, large 3D graffiti-style Chinese characters "生日快乐" (Happy Birthday), with blue-to-yellow gradient edges. The text is surrounded by cursive English script "Smile". Floating around the scene are hand-drawn style palettes, smiley-face stars, colorful light ribbons, and sparkling light dots. The overall style is joyful, festive, and energetic, with a hand-drawn illustration aesthetic and vivid, high-contrast colors. No other text, no watermarks, no logos, no borders.
