Create a minimalist line art illustration depicting a city skyline enveloped in a thick layer of fog. The scene should feature iconic skyscrapers with distinct outlines, their tops disappearing into the mist, creating a sense of depth and mystery. Include elements such as street lamps and silhouetted trees in the foreground, partially obscured by the fog to enhance the atmosphere. The overall composition should convey a tranquil yet eerie mood, with soft, diffused lighting suggested through subtle gradient effects in the background. The monochrome palette will emphasize the outlines and textures of the buildings, while the fog adds a layer of intrigue, inviting viewers to explore the hidden details within the urban landscape.