<!--	use class .btn-variant-outline along with class .btn   -->
<button class="btn btn-primary-outline">Primary</button>
<button class="btn btn-secondary-outline">Secondary</button>
<button class="btn btn-ternary-outline">Ternary</button>
<button class="btn btn-success-outline">Success</button>
<button class="btn btn-warning-outline">Warning</button>
<button class="btn btn-danger-outline">Danger</button>
<button class="btn btn-dark-outline">Dark</button>