// flex布局 $flex-directions: row, row-reverse, column, column-reverse; @each $v in $flex-directions { .flex-#{$v} { @include flex($v); } } $justify-content: start, end, center, between, around, evenly; @each $v in $justify-content { .justify-#{$v} { @if ($v == 'start') { justify-content: flex- + $v; } @else if($v == 'start') { justify-content: flex- + $v; } @else { justify-content: $v; } } } $align-items: start, end, center, baseline, stretch; @each $v in $align-items { .items-#{$v} { @if ($v == 'start') { align-items: flex- + $v; } @else if($v == 'start') { align-items: flex- + $v; } @else { align-items: $v; } } }