// rem fallback - credits: http://zerosixthree.se/

@function calculateRem($size) {
  $remSize: $size / 16px;
  @return $remSize * 1rem;
}

@mixin font-size($size) {
  font-size: $size;
  font-size: calculateRem($size);
}

@mixin center($xy:xy) {
    @if $xy == xy {
        left: 50%;
        top: 50%;
        bottom: auto;
        right: auto;
        @include transform(translateX(-50%) translateY(-50%));
    }
    @else if $xy == x {
        left: 50%;
        right: auto;
        @include transform(translateX(-50%));
    }
    @else if $xy == y {
        top: 50%;
        bottom: auto;
        @include transform(translateY(-50%));
    }
}

Implement px to rem converter mixin and center mixin (horizontal, vertical or both)
Implement px to rem converter mixin and center mixin (horizontal, vertical or both)
