Vertical 9:16 social media video, modern bright gym interior with mirrors and exercise balls in b...

Vertical 9:16 social media video, modern bright gym interior with mirrors and exercise balls in background, exactly like the reference image. A miniature athletic young woman with long dark hair is sitting comfortably on the back of a very muscular man who is holding a difficult plank position on the grey gym mat, hands on the floor, body tense, face showing effort. The woman looks playful and smiling, she turns her head slightly toward the camera and says in a cheerful voice "No pain, no gain~". Suddenly a bright magical pink-white "LVL UP" game UI effect flashes above her head with sparkles. She begins to magically grow much taller and larger in overall scale while still sitting on his back. At first her bare feet dangle freely in the air, not reaching the floor. She looks surprised but delighted, eyes wide, pleasant shock on her face. As the growth continues, her body stretches out smoothly: her spine and torso elongate noticeably, her legs lengthen dramatically, and her lower body and hip area visibly expand in size and volume. All new proportions are fully retained — the enlarged lower body and stretched shape stay at their new scale without returning. The growth becomes very dramatic and noticeable: she becomes significantly larger and taller than him, her head and shoulders tower well above him. The man underneath starts to struggle, his arms shaking, then his plank completely collapses and he lowers gently onto the mat under her new size. In the end she is much taller and much bigger than the man (clearly towers over him), still sitting on him playfully, looking amazed and amused at her new size. He looks up in total disbelief and shock. Smooth cinematic camera, slow push-in during the strong transformation, soft warm gym lighting with subtle magical glow, realistic physics on clothing and hair, dynamic motion, humorous fantasy-comedy tone, high detail, natural anatomy, focus on magical growth, clear scale change and funny reactions.