Makoto Shinkai-style cinematic sky background illustration

Use a wide 16:9 composition, as if it were a single frame taken directly from a Shinkai movie. The sky must be the absolute protagonist, occupying most of the frame. Paint an extremely spectacular, detail-rich sky: for example, a towering cumulonimbus cloud stretching to the heavens, or gorgeous evening clouds where orange, purple, and deep blue gradients interweave, or a huge rainbow arching over the city after the rain. The lighting should be at the most magical time of day, either Golden Hour or Blue Hour. Include strong yet soft lens flares in the sky, with sunlight streaming through gaps in the clouds to form clear volumetric rays, and tiny glowing dust motes and light particles drifting in the air.