Create a soft, grainy gradient background with a sandpaper texture effect. The gradient should transition smoothly from sunset orange at the bottom, blending into light purple in the middle, and finally into sky blue at the top. The texture should resemble the roughness and subtle grain of sandpaper, with fine details to enhance the tactile feel. Ensure the colors blend smoothly, with a natural, serene vibe that evokes the colors of a sunset sky, while maintaining a textured, gritty finish throughout