Underwater Diving Board Portal

Create a surreal cinematic underwater scene showing {argument name="main structure" default="the world's highest diving board"} standing on the ocean floor like an abandoned brutalist concrete tower. The image is vertical, wide-angle, and photorealistic, with the camera looking slightly upward through blue-green water toward the rippling surface. On the left side, place one tall algae-stained concrete diving tower with exactly four visible protruding platforms: one highest long springboard near the top, one small middle landing with a railing, one lower angled diving platform, and one broad side platform near the base with a ladder descending beside it. At the very tip of the highest board stands exactly one tiny human diver in a swimsuit, silhouetted and preparing to jump, emphasizing scale and vertigo. The seafloor is flat, sandy, and littered with small rocks and sediment. In the foreground, create exactly one large square opening cut into the ocean floor, like an impossible portal or pool, glowing from within with {argument name="portal light color" default="warm golden yellow"} light and suggesting a deeper world beneath the seabed. Include exactly 20 small fish scattered across the midwater to the right of the tower, plus a few dark distant specks, but keep them subtle. Use hazy volumetric underwater lighting, suspended particles, muted teal-blue color grading, aged concrete textures, moss, barnacles, soft caustics, and a dreamlike mysterious atmosphere. No text, no people besides the single diver, no modern signage, no extra structures, no watermark.