Can I 2

I'm currently working on a school project for which we're supposed to build a responsive website. For the large format, I have a standard navigation menu with everything already set up. However, I'd like to create a hamburger menu for the small format. Could I simply add two <nav> tags to the source code and then control them separately using CSS?

For example, the first is called class="navgross" and the other class="navklein"

And then for the large size in the CSS navklein {display: none;} and for the small size navgross {display:none;} ?

Unfortunately, we are not allowed to use JavaScript either…