Great Barrier Reef Retro Travel Poster

An editorial travel poster illustration of [the Great Barrier Reef, Australia]. Style: flat vector illustration, ultra-clean minimalism, mid-century modern travel poster aesthetic inspired by vintage tourism prints and Scandinavian graphic design, featuring crisp shapes, flat color blocks, vibrant harmonious tones, with no photorealism, no gradients, and no textures. Composition: vertical split-level view showing both underwater and above-water scenes. Underwater foreground: a coral reef filled with stylized corals in pink, orange, yellow, and red, tropical fish with stripes and bright accents, and a large sea turtle swimming toward the right in clear turquoise water. Midground: a female snorkeler wearing fins and a mask swims horizontally just below the water's surface as subtle light rays penetrate the sea. Above-water background: a calm ocean with shallow reef patches, a white leisure boat anchored on the left, a small distant sailboat, and soft green rolling hills along the horizon under a bright blue sky with fluffy white clouds and soaring birds. Lighting: bright, warm daylight. Typography at the bottom center: bold uppercase text "[GREAT BARRIER REEF]", followed below by smaller spaced-out text "[AUSTRALIA]", separated by divider lines with a small coral icon.