<button class="btn">Default</button>
    <button class="btn btn-primary">Primary</button>
    <button class="btn btn-info">Info</button>
    <button class="btn btn-success">Success</button>
    <button class="btn btn-warning">Warning</button>
    <button class="btn btn-danger">Danger</button>
    

    
    <button class="btn btn-rounded">Default</button> 
    <button class="btn btn-primary btn-rounded">Primary</button>
    <button class="btn btn-info btn-rounded">Info</button>
    <button class="btn btn-success btn-rounded">Success</button>
    <button class="btn btn-warning btn-rounded">Warning</button>
    <button class="btn btn-danger btn-rounded">Danger</button>