Border icons
<a href="#" class="social-icon si-border si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon si-border si-border-round si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-lg si-border si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-lg si-border si-border-round si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-sm si-border si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-sm si-border-round si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
Dark icons
<a href="#" class="social-icon si-dark si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon si-dark si-dark-round si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-lg si-dark si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-lg si-dark si-dark-round si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>
<a href="#" class="social-icon-sm si-dark si-facebook">
<i class="fa fa-facebook"></i>
<i class="fa fa-facebook"></i>
</a>