Buttons

.btn

<button type="button" class="btn">default</button>
<button type="button" class="btn" disabled>default</button>
<a href="..." class="btn">link</a>

.btn.btn-outline

<button type="button" class="btn btn-outline">primary</button>
<button type="button" class="btn btn-outline" disabled>primary</button>
<a href="..." class="btn btn-outline">link</a>

.btn.btn-primary

<button type="button" class="btn btn-primary">primary</button>
<button type="button" class="btn btn-primary" disabled>primary</button>
<a href="..." class="btn btn-primary">link</a>

.btn.btn-icon

<button type="button" class="btn btn-icon"><Icon/></button>
<button type="button" class="btn btn-icon" disabled><Icon/></button>
<a href="..." class="btn btn-icon">link</a>