@mixin nav-spacer($name, $size, $orientation) { .spacer.#{$name} { width: $size; } } .body_setting { @extend .body_ui; background-color: $color_back_basic; } #frame { @extend %flex-column; position: relative; height: 100%; header, aside, footer { border: 1px solid transparent; } &>header { background-color: rgba(0, 0, 0, .1); } main { @extend %flex-row; flex: 1; aside { background-color: rgba(255, 255, 255, .1); } section { flex: 1; } } } .io { .spacer { margin: 0; border: $border_dotted; padding: 0; opacity: .25; } @include nav-spacer('a', $space_double, false); @include nav-spacer('b', $space_small, false); }