Create an image of a joyful runner participating in a marathon. The runner, a young individual, wears a bright, patterned t-shirt that features abstract designs in various colors. They sport navy blue shorts and black leggings that have reflective stripes for visibility. The runner is smiling and giving a thumbs-up gesture. In the background, various runners in athletic attire—some in neon colors and others in solid hues—are seen in motion, displaying a lively atmosphere. The scene is set outdoors with blurred city buildings and colorful flags lining the course. Include a watermark in a bold, diagonal style across the image that reads "EVENT PHOTOS."