How to make the width of a customized dropdown menu responsive to various devices?

Hi everyone.

In my portfolio project, I have designed a dropdown menu for anchor links to flow to page sections.

My problem is that I don’t know how I can make this dropdown menu size responsive to all devices’ breakpoints. It is important, because when it comes to mobile breakpoints I want this menu to take 100% screen width for all various mobiles.

I here send a screenshot of the menu and how it looks now on different mobile devices. And also my read-only link.
PS: I am a total novice :sweat_smile:

iPhone SE

iPhone 12

I would appreciate any advice.

Thanks a lot :slight_smile:

Here is my site Read-Only: