Valueless href attribute does not validate at W3C

I love this theme.

I’m trying to make my Eighties-themed website validate using the HTML/CSS validator tools at W3C.org. The validator complains that several anchors in the theme’s templates contain the href attribute that doesn’t have a value, like these two for the main menu toggles (which I love the minimal simplicity of)–

<div class="site-toggles">
   <a href class="main-navigation-toggle"><i class="fa fa-bars"></i></a>
   <a href class="widget-area-toggle"><i class="fa fa-align-right"></i></a>
</div>

I’m thinking that the href was intentionally left without a URL in order to implement the functionality of the navigation toggle widgets. But I’m wondering if there is some way to edit the templates to cause the valueless href attributes not to raise an error with validator tools.