Define and preview custom responsive breakpoints for your CSS.
@media (min-width: 640px) { /* sm */ }
@media (min-width: 768px) { /* md */ }
@media (min-width: 1024px) { /* lg */ }
@media (min-width: 1280px) { /* xl */ }
@media (min-width: 1536px) { /* 2xl */ }