Illustration of a joyful child sitting on the sandy beach, engagingly building a sandcastle. The child has a cute face framed by blonde pigtails, and their big, expressive eyes are depicted with extreme detail. They are using a colorful plastic bucket amidst shells and sea life under the warm sunlight, which casts dramatic lighting and creates a subtle lens flare effect. The scene is captured in a low-angle close-up shot, highlighting the child's happiness and concentration. Their delightful smile and the intricate design of the sandcastle add depth to the image. The atmosphere evokes a sense of carefree summer days, with the ocean breeze gently tousling the child’s hair. The visual quality is stunningly clear and vibrant, with 16k UHD and HDR enhancing every detail.