Need help on this project

HTML-CSS
#1

Build a Technical Documentation Page https://codepen.io/Karons101/pen/pYPNpJ

13. When I click on a navbar element, the page should navigate to the corresponding section of the “main-doc” element (e.g. If I click on a “nav-link” element that contains the text “Hello world”, the page navigates to a <section> element that has that id and contains the corresponding <header>.

#2

Line 21 has its quotes on the next line.

#3

Thank U so much, it worked well and perfect… U are so kind.

#4