Set background of unfound categories (# < 1) to white.

It would be nice if the background of categories [Valid Links, Valid redirect links, Warnings, Invalid links] were white until the count > 0.
Quick mockup below.

<img width="375" height="442" alt="Image" src="https://github.com/user-attachments/assets/c026291c-be3a-4d65-a5f7-957005f1ff35" />