xs sm md lg xl xxl

Fill

Lorem Ipsum
.flex-fill
Lorem Ipsum
.flex-fill
Lorem Ipsum
.flex-fill
.flex-lg-fill
.flex-fill
.flex-lg-fill

Align Items (to container)

.align-items-start

Caja 1
Caja 2
Caja 3

.align-items-center

Caja 1
Caja 2
Caja 3

.align-items-end

Caja 1
Caja 2
Caja 3

.align-items-strech

Caja 1
Caja 2
Caja 3

Align Self (to element)

.align-self-start
.align-self-center
.align-self-end
.align-self-stretch

Auto Margins

.me-auto (margin end)
Caja 2
Caja 3
Caja 1
Caja 2
.ms-auto (margin start)
.mb-auto (margin bottom)
Caja 2
Caja 3
Caja 1
Caja 2
.mt-auto (margin top)