First of al, sorry for my skeletal English.
I was working on with the portfolio webpage challenge. Then the problem came up: class navbar-right or mr-auto did not work at all. After a while a created more
But then every thing under tag such as footer,… disappear and it cost me 2 hours to found out nothing.
Here is my codepen: https://codepen.io/nhan863240/pen/gezVWp?editors=1000
Thank you all very much!