Flex-box: Align last row to grid

Question

I have a simple flex-box layout with a container like:

.grid {
  display: flex;
  flex-flow: row wrap;
  justify-content: space-between;
}

Answer 1

I made a SCSS mixin for it.

@mixin last-row-flexbox($num-columns, $width-items){

  $filled-space: $width-items * $num-columns;
  $margin: calc((100% - #{$filled-space}) / (#{$num-columns} - 1));

  $num-cols-1 : $num-columns - 1;

  &:nth-child(#{$num-columns}n+1):nth-last-child(-n+#{$num-cols-1}) ~ & {
    margin-left: $margin;
  }
  @for $i from 1 through $num-columns - 2 { 
    $index: $num-columns - $i;
    &:nth-child(#{$num-columns}n+#{$index}):last-child{
      margin-right: auto;
    }
  }
}

This is the codepen link: http://codepen.io/diana_aceves/pen/KVGNZg

You just have to set the items width in percentage and number of columns.

I hope this can help you.