Breakpoint prefix	Minimum width	CSS
sm	640px	@media (min-width: 640px) { 256*2+128 }
md	768px	@media (min-width: 768px) { 640+128 }
lg	1024px	@media (min-width: 1024px) { 768+256 }
xl	1280px	@media (min-width: 1280px) { 1024+256 }
2xl	1536px	@media (min-width: 1536px) { 1280+256 }