@mixin nav-spacer($name, $size, $orientation) { .spacer-#{$name} { width: $size; margin: 0; border: $border_dotted; opacity: .25; } } #frame { position: relative; height: 100%; header, aside, footer { border: 1px solid transparent; } &>header { background-color: rgba(0, 0, 0, .1); } main { aside { background-color: $color_brighter; } } } .frame-flex { display: flex; flex-direction: column; gap: $space_basic; main { flex: 1; aside, section { height: 100%; } } } .io { .spacer { width: $space_double; margin: 0; border: $border_dotted; opacity: .25; } @include nav-spacer('a', $space_double, false); @include nav-spacer('b', $space_small, false); }