How to omit dark and rounder border?

[codayon]

After installation I tried running,

picom --backend glx --vsync

In Firefox, when I hover the tabs it makes the window look like weird.

simplescreenrecorder-2025-10-30_13.36.17.webm

I also tried using the sample config but similar output

[codayon]

While tinkering with the config it was fixed automatically.