Otome game CG illustration, exquisitely beautiful, inside a ...

Otome game CG illustration, exquisitely beautiful, inside a massive underwater glass tunnel. Sunlight filters through the seawater, casting dynamic water ripples and light patterns (caustics). A couple: the male lead, wearing an elegant deep-sea blue formal suit, is taking a glowing pearl necklace out of a seashell box to present to the female lead; the female lead is wearing an aqua-blue gradient tulle dress, her expression filled with surprise and emotion. Outside the glass are colorful coral reefs, schools of fish, and a giant manta ray. Dreamy atmosphere, translucency, high detail, intricate clothing details, character close-up, facial expression close-up. 8k resolution. The scene features subtle hints of green and brown.