It is about the width of speedreader feature on brave desktop

Hey Brave team, I read articles a lot online. And definitely love the speedreader feature on brave desktop. The only thing that is bugging me that It doesn’t cover the full width of my screen. I tried using it in developer mode and I just changed a value in CSS section, and It fits perfectly(I am no professional). If you guys can please fix it, it will be great. Thank you guys!
I tried this: