Basic
Use the .btn .btn-{color}
classes.
Buttons .btn-outline
Use the .btn .btn-outline-{color}
classes.
Button Sizes
Use the .btn-lg
or .btn-sm
classes.
Button States
Use the .disabled
or .btn-progress
classes.
Icon Button
Use the .btn-icon
and .icon-left
classes.
Only Icon Button
Use the .btn-icon
class.
Sizes.