Bootstrap Utility Classes

.m-3 # margin all sides
.mt-3 # margin top
.mb-3 # margin bottom
.ms-3 # margin start (left)
.me-3 # margin end (right)
.p-3 # padding all sides
.pt-3 # padding top

.d-none # hide element
.d-block # display block
.d-inline # display inline
.d-inline-block # display inline-block
.d-flex # display flex
.d-md-none # hide on medium+ screens

.text-start # align left
.text-center # align center
.text-end # align right

.text-primary # blue text
.text-success # green text
.text-danger # red text
.text-warning # yellow text
.text-muted # muted text

.bg-primary # blue background
.bg-success # green background
.bg-danger # red background
.bg-light # light background
.bg-dark # dark background

.border # all borders
.border-top # top border
.border-0 # remove borders
.border-primary # blue border
.rounded # rounded corners
.rounded-circle # circle