Envision a flat design illustration of a waterfront scene where fog rolls in from the water, creating a tranquil and atmospheric setting. The image should feature simplified boats, piers, and buildings along the shoreline, all rendered in a vibrant yet muted color palette. The fog should be depicted using soft gradients that blend seamlessly with the water, enhancing the sense of calm. Incorporate elements like seagulls or people enjoying the waterfront, designed in a minimalist style, to add life to the scene. The overall composition should convey a peaceful and inviting atmosphere, inviting viewers to immerse themselves in this foggy waterfront. Keywords: "flat design," "foggy waterfront," "minimalist illustration," "tranquil atmosphere."