Generate an SVG (width="1200" height="900" viewBox="0 0 1200 900") as a birthday greeting card illustration. Warm hand-drawn watercolor style. Draw a cheerful 3-tiered birthday cake at lower-center — tiers in coral (#F97316) and cream (#FFF3E8) with soft gradient fills, 5 lit candles on top with teardrop flame shapes in #FBBF24. Float 3 balloon shapes (rounded oval bodies with thin string paths) in coral and golden yellow upward into the upper canvas. Scatter small 4-pointed stars and confetti rectangles in #FBBF24 and #FB923C across the upper area. Add soft watercolor blob shapes behind the cake in #FFF3E8 (opacity 0.4). Soft rounded edges, SVG gradients throughout. No text, no labels, no emoji. Output raw SVG code only starting with <svg.

The image shows a birthday cake with candles and balloons, set against a white background. The cake is decorated with colorful frosting and sprinkles, and the candles are lit, creating a festive atmosphere.