Default buttons use class btn. If you want add color use class bg-@colorname.
Add class btn-roundedto get rounded corners.
Add class btn-outlineto get outline button.
Add btn-rounded , btn-outlineto quickly create rounded and outline button.
Add class disabledto get disabled button.
Add class btn-blockto get block button.
Add class btn-xs, btn-sm, btn-md ,btn-lgfor additional sizes.
Add class activeto get active button
Add class circle-xs, circle-sm, circle-md, circle-lgto create circle button.
Wrap a series of buttons with btnin btn-group.
Add class btn-@socialnameto create social button.
Add for btn-@socialnameclass circle-xs, circle-sm, circle-md, circle-lgto create circle social button.