简约风蓝天白云绿色草地清新自然背景

minimalist background, green and blue color scheme, fresh and natural style, scene of grassland and blue sky, grassland in lower half, blue sky in uer half, peaceful and serene atmosphere, open and spacious environment, no decorative elements, no text, natural gradient background, bright and fresh visual effect, conveying a sense of peace and natural beauty --ar 3:2