<!-- 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>