How to keep a pinned tab the same size as the regular tabs?
When I pin a tab it shows only its favicon, which is very small. How do I make them wider?
You can't change the width of a pinned tab. That is how pinned tabs work. They are positioned at the at the left end of the Tab bar and consist only of the favicon. That makes it easy to see where pinned tabs end and regular tabs start. This also allows for more space for regular tabs and have a lot of tabs pinned.