A 3D Pixar-style cartoon illustration of a young brother and sister standing together against a warm beige studio backdrop. 

The composition features:

1. The brother on the left with dark messy hair holding a large bunch of metallic silver, navy-blue, clear confetti, and heart-shaped balloons, while handing a single balloon to his sister.

2. The sister on the right with long dark wavy hair in a high ponytail, smiling happily with hands clasped together.

3. To keep the design completely unique, both characters wear matching casual streetwear outfits: deep navy-blue crewneck sweatshirts, black cargo pants, and clean white sneakers.

Top-right calligraphic script typography reads "Bahan • Bhai" in crimson red and black with small drawn hearts. Soft 3D animation studio lighting, smooth textures, 8k render. [Reference Image Rule: If I upload a photo (brother and sister or kids), preserve our exact facial features, skin tone, eye shape, and facial structure from my uploaded image while converting us into these 3D cartoon sibling characters with this custom navy outfit style. If no photo is uploaded, generate the full scene directly.] --ar 4:5