Please how can I make the border to function, I can only put margin

Question

To use CSS and code "margin and border"
https://code.sololearn.com/WNm415uTD8a6/?ref=app
https://code.sololearn.com/WNm415uTD8a6/?ref=app

Answer 1

Something like:
border: solid red 4px;

Answer 2

Thanks