How to make awesome icons resize relative to screen?

Could anyone please me with this question. Here is my code:

<a class="btn btn-default" href=""><i class="fa fa-twitter fa-lg" id="twitterIcon" aria-hidden="true"></i> Twitter</a>

icons are just fonts, use a different unit in your CSS.

Try this out. Make a new div class and name it "container-fluid"
The class “container-fluid” will consistently resize all shapes and icons relative to your screen and what device you’re using. Put in under your first div element and close it and it should work

Insightful, thank you!

Thank you very much indeed.