Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

// Transform a value into rem
// Assuming baseline is set to 10px on :root/html
@function rem($value, $baseline: 10px) {
    @if type-of($value) == list {
        $result: ();
        @each $e in $value {
            $result: append($result, rem($e));
        }
        @return $result;
    } @else {
        @if $value == 0 { @return 0; }
        @if $value == 'auto' { @return auto; } // added in the option to pass in auto
        @return if(unit($value) == px, $value / $baseline * 1rem, $value);
    }
}

// Use rem units with px fallback
@mixin rem($properties) {
    @each $property, $value in $properties {
        @if (type-of($value) == number and $value != 0) {
            $value: if(unitless($value), $value * 1px, $value);
        }

        #{$property}: $value;
        #{$property}: rem($value);
    }
}

.test {
    @include rem((
        padding: 20px 0 0px 3vh,
        width: 300px,
        margin: 20px auto 20px auto,
        height: 350px,
        line-height: 20px
    ));
}

SassMeister-output.css

.test {
  padding: 20px 0 0px 3vh;
  padding: 2rem 0 0 3vh;
  width: 300px;
  width: 30rem;
  margin: 20px auto 20px auto;
  margin: 2rem auto 2rem auto;
  height: 350px;
  height: 35rem;
  line-height: 20px;
  line-height: 2rem;
}