How can I make the navigation bar sticky?

Question

https://code.sololearn.com/WQxkvVREn9mS/?ref=app

Answer 1

Try to add this
ul {
position: fixed;
width: 95%;
}

https://code.sololearn.com/We35Ps96vbD4/?ref=app

Answer 2

https://www.w3schools.com/howto/howto_js_navbar_sticky.asp
Try this... it's easy to understand