I made this grid system with 12 columns, the detail is that I want to modify it in a way that I don’t know if it is possible. The modification consists of adding two more columns, one at the beginning and one at the end, those two columns would be 1fr. I did that part, but what I would like to do is that between column 1 (1fr) and 2 (84px) there is no gap and the same case between column 13 (84px) and 14 (1fr). I attach the code that I have so far.

i tried the code above.