Highlight coeff currently on

currently kdrag is always highlighted even when on different coeff

<img width="1109" height="415" alt="Image" src="https://github.com/user-attachments/assets/3f6d70dd-8c52-4082-be3a-6f7354ddaae4" />

<img width="1109" height="415" alt="Image" src="https://github.com/user-attachments/assets/a25462bc-6019-4325-be31-94e1f67a9d69" />