xs sm md lg xl xxl

.bg-primary

.bg-secondary

.bg-success

.bg-danger

.bg-warning

.bg-info

.bg-light

.bg-dark

.bg-white

.bg-transparent

.bg-primary .bg-gradient

.bg-secondary .bg-gradient

.bg-success .bg-gradient

.bg-danger .bg-gradient

.bg-warning .bg-gradient

.bg-info .bg-gradient

.bg-light .bg-gradient

.bg-dark .bg-gradient

.bg-white .bg-gradient

.bg-transparent .bg-gradient

default

bg-opacity-75

bg-opacity-50

bg-opacity-25

bg-opacity-10

default

bg-opacity-75

bg-opacity-50

bg-opacity-25

bg-opacity-10