.ba { border-style: solid; border-width: 1px; }
.bt { border-top-style: solid; border-top-width: 1px; }
.br { border-right-style: solid; border-right-width: 1px; }
.bb { border-bottom-style: solid; border-bottom-width: 1px; }
.bl { border-left-style: solid; border-left-width: 1px; }
.bn { border-style: none; border-width: 0; }
@media screen and (min-width: 30em) {
 .ba-ns { border-style: solid; border-width: 1px; }
 .bt-ns { border-top-style: solid; border-top-width: 1px; }
 .br-ns { border-right-style: solid; border-right-width: 1px; }
 .bb-ns { border-bottom-style: solid; border-bottom-width: 1px; }
 .bl-ns { border-left-style: solid; border-left-width: 1px; }
 .bn-ns { border-style: none; border-width: 0; }
}
@media screen and (min-width: 30em) and (max-width: 60em) {
 .ba-m { border-style: solid; border-width: 1px; }
 .bt-m { border-top-style: solid; border-top-width: 1px; }
 .br-m { border-right-style: solid; border-right-width: 1px; }
 .bb-m { border-bottom-style: solid; border-bottom-width: 1px; }
 .bl-m { border-left-style: solid; border-left-width: 1px; }
 .bn-m { border-style: none; border-width: 0; }
}
@media screen and (max-width: 60em) and (orientation: landscape) {
 .ba-ml { border-style: solid; border-width: 1px; }
 .bt-ml { border-top-style: solid; border-top-width: 1px; }
 .br-ml { border-right-style: solid; border-right-width: 1px; }
 .bb-ml { border-bottom-style: solid; border-bottom-width: 1px; }
 .bl-ml { border-left-style: solid; border-left-width: 1px; }
 .bn-ml { border-style: none; border-width: 0; }
}
@media screen and (min-width: 60em) {
 .ba-l { border-style: solid; border-width: 1px; }
 .bt-l { border-top-style: solid; border-top-width: 1px; }
 .br-l { border-right-style: solid; border-right-width: 1px; }
 .bb-l { border-bottom-style: solid; border-bottom-width: 1px; }
 .bl-l { border-left-style: solid; border-left-width: 1px; }
 .bn-l { border-style: none; border-width: 0; }
}