Errno 22 Invalid Argument Python

I’m trying to copy one file’s content to another, and error appears, what do i do wrong?

for file in os.listdir('offer'):     if '.css' in file:         print(file)         with open(f'offer/{file}', 'r+') as f:             with open('offer/id.css', 'w+') as style_file:                 shutil.copyfile(f'offer/{f}', f'offer/{style_file}')