Safari won’t close on desktop

one day I was just quitting different apps on the desktop and when I got to safari I must have clicked something, because it set it to almost part of the background. No matter what I did it wouldn’t go even if I tried making a new custom desktop and moving it there and deleting the desktop it would not delete. It does not affect the MacBook in anyway, it is just very annoying and it blocks out the desktop background and any apps behind it. Please help