We use the solid style of Font Awesome 5 icons.
Icons are not included in our CSS for third parties.
We encoracge you to use the same set of icons as us. Most apps will be satisfied with the free version of Font Awesome 5. For a complete overview, please refer to https://fontawesome.com/icons?d=gallery&s=solid&m=free
If you use the webfont solution, like us, you can paste icons like this:
<i class="fas [icon name]"></i>
Please observe that we use some icons for specific features in Xena. We encourage you to obey this usage so the end user doesn't get confused.