Design a main visual for an eco-friendly parent-child activity on an A1 vertical banner. The scene theme is a Hong Kong seaside parent-child cleaning event, with a beach and rocky shore under blue sky and white clouds, clean clear water, distant islands and mountains, evoking the Longgu Bay area. In the foreground there are 3–5 children and 2–3

"Design a main visual for an eco-friendly parent-child activity on an A1 vertical banner. The scene theme is a Hong Kong seaside parent-child cleaning event, with a beach and rocky shore under blue sky and white clouds, clean clear water, distant islands and mountains, evoking the Longgu Bay area. In the foreground there are 3–5 children and 2–3 parents, all wearing gloves, holding trash pickers and garbage bags, picking up plastic bottles, foam and plastic bags on the beach. Everyone looks happy and cooperative. The style is flat illustration with simple lines, cute character designs suitable for kindergarten and early primary school audiences, bright warm colors mainly blue, green, and yellow. Reserve about one quarter of the top area as blank sky for Chinese title text, and a horizontal blank area at the bottom for sponsor and organizer logos. The overall atmosphere is positive and hopeful, highlighting the message "Parents and children together protect the ocean and natural environment"."