semi-design/packages/semi-foundation/checkbox/rtl.scss

$module: #{$prefix}-checkbox;
$inner-width: $width-icon-medium;

.#{$prefix}-rtl, 
.#{$prefix}-portal-rtl {
    .#{$module} {
        direction: rtl;

        input[type="checkbox"] {
            left: auto;
            right: 0;
        }
    }

    .#{$module}Group {
        direction: rtl;
    }
}