Create a 15-second 4K ultra-realistic vertical video, 16:9, 29.97fps, cinematic soft lighting, cold gentle color palette, no facial display throughout the video, the protagonist is a white American woman with pure black hair, four consecutive and smooth shots. Shot 1: Extreme close-up of the woman’s head tied into a ponytail, her hair is extremely greasy and covered with a lot of dandruff, her hands keep pulling the hair apart to expose the scalp, and the scalp is full of obvious dandruff, the texture of greasy hair and dandruff is hyper-clear and realistic. Shot 2: Close-up shot, a pair of hands hold a triangular soap and keep still under a shower head, the shower head sprays warm water continuously on the triangular soap, water droplets flow down the soap surface naturally, the dynamic details of water flow are clear. Shot 3: In the same bathroom, the woman stands under the shower head with her back to the camera, her body is wrapped in a clean white bath towel, her black hair is covered with light green rich and delicate foam, her hands keep rubbing and scratching her hair vigorously, the movement is natural and smooth. Shot 4: Extreme close-up of the woman’s head in a bright bedroom, her hair is freshly washed and blow-dried, the hair is super smooth, fluffy and voluminous, no greasiness and no dandruff at all, her hands keep pulling the hair apart to show the neat hair parting, the hair texture is soft and shiny, the overall picture is clean and comfortable.