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 caustics. A couple: the male lead wearing an elegant deep-sea blue formal suit, taking out a glowing pearl necklace from a seashell box to gift it to the heroine; the heroine wearing a water-blue gradient tulle gown with a joyful expression. Outside the glass are colorful coral reefs, schools of fish, and a giant manta ray. Dreamy atmosphere, transparency, high detail, intricate clothing details, character close-up, facial expression close-up. 8k resolution. Hints of green and brown tones in the image.