Responsive

Some of utility classes can be applied conditionally at different breakpoints, which makes it a piece of cake to build complex responsive interfaces without ever leaving your HTML.

The classes are named using the format .u-{class-name}@{breakpoint}-{up|down}.

It should be noted here, that when we write up or down, this includes the breakpoint itself. For example the utility class .u-display-none@md-down would work only at the breakpoint md and below.