Create an SVG illustration of a cute duck riding a bicycle on a sunny day. The scene should include: a bright yellow sun with rays in the upper-right corner, a light blue sky gradient, rolling green hills in the background, and a simple winding path. The duck should be yellow with an orange beak and a small wing, sitting on a red bicycle with round wheels and visible spokes. Add 2–3 small white clouds and colorful flowers along the path. The SVG should be entirely self-contained in a single file, sized at 400×400 pixels.