Button

Button

Default Primary Invert 
<a href="" class="btn btn-default ">
    Default
</a>

<a href="" class="btn btn-primary ">
    Primary
</a>

<a href="" class="btn btn-invert ">
    Invert
</a>

Button small

Default sm Primary sm Invert sm 
<a href="" class="btn btn-default btn-sm ">
    Default sm
</a>

<a href="" class="btn btn-primary btn-sm ">
    Primary sm
</a>

<a href="" class="btn btn-invert btn-sm ">
    Invert sm
</a>

Button Icon 

<a href="" class="btn btn-default icon ">
    <i class="fa fa-paper-plane-o"></i>
</a>


<a href="" class="btn btn-primary icon ">
    <i class="fa fa-paper-plane-o"></i>
</a>

<a href="" class="btn btn-invert icon ">
    <i class="fa fa-paper-plane-o"></i>
</a>