Create a soft abstract gradient background with smooth transitions. The gradient should consist of sunset orange occupying 40% on the left, blending into sky blue which covers 30% in the middle, and transitioning into light purple for the remaining 30% on the right. The transitions between the colors should be seamless and subtle, with a slightly grainy texture to give it a vintage, retro feel. Focus on ensuring the gradient is smooth and balanced, with a soft-focus effect that enhances the calming, atmospheric tones.