Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.5)
// Compass (v1.0.1)
// ----

// Vars
// -------------------------------------------------------------------------------------------------

/**
 * Default font size for all text in pixels
 */
$rhythm-base-font-size: 16px !default;

/**
 * Distance between text baselines in pixels.
 */
$rhythm-base-line-height: 21px !default;

/**
 * The length unit in which to output rhythm values. Supported values: px, em, rem.
 * Percent units can't be used since they make calculating padding and margins impractical,
 * and percentage borders are not valid or supported in css.
 */
$rhythm-unit: rem !default;

/**
 * Allows the `adjust-font-size-to` mixin and the `rhythm-lines-for-font-size` function
 * to round the line height to the nearest half line height instead of the
 * nearest integral line height to avoid large spacing between lines.
 */
$rhythm-round-to-nearest-half-line: false !default;

/**
 * Ensure minimum leading above / below text. Number of lines will be increased if necessary.
 */
 $rhythm-min-line-leading: 2px !default;

/**
 * Establish a rhythm throughout the document using a font-size and line-height.
 *
 * @param {Number} $font-size ($rhythm-base-font-size)
 *  The font-size to use as base
 *
 * @output
 *  Render html element with `font-size` and `line-height` set.
 */

// Default font-size for all browsers
$rhythm-browser-default-font-size: 16px;

// The leader is the amount of whitespace in a line.
// It might be useful in your calculations.
$rhythm-base-leading: convert-length($rhythm-base-line-height - $rhythm-base-font-size, $rhythm-unit, $rhythm-base-font-size);

// The half-leader is the amount of whitespace above and below a line.
// It might be useful in your calculations.
$rhythm-base-half-leader: $rhythm-base-leading / 2;

// @private Whether the rhythm output is in absolute units (px) or not (em, rem)
$rhythm-relative-font-sizing: if($rhythm-unit == px, false, true);

$rhythm-invalid-value-error: "Invalid Value Error";
$rhythm-invalid-unit-error: "Invalid Unit Error";
$rhythm-last-error: null;
$rhythm-under-test: false;
$rhythm-error-thrown: false;

// Support
// -------------------------------------------------------------------------------------------------

@function rhythm-throw-error($error, $message) {
  @if $rhythm-under-test {
    @if not $rhythm-error-thrown {
      $rhythm-error-thrown: true !global;
      $rhythm-last-error: $error !global;
    }
  } @else {
    @error "#{$error} #{$message}";
  }
  @return null;
}

@function rhythm-validate($font-size, $line-height) {
  // Validate units
  @if unit($font-size)   != 'px' {
    $error: rhythm-throw-error($rhythm-invalid-unit-error, "$rhythm-base-font-size must resolve to a pixel unit.");
  }
  @if unit($line-height) != 'px' {
    $error: rhythm-throw-error($rhythm-invalid-unit-error, "$rhythm-base-line-height must resolve to a pixel unit.");
  }
  @if $rhythm-unit != 'px' and $rhythm-unit != 'em' and $rhythm-unit != 'rem' {
    $error: rhythm-throw-error($rhythm-invalid-unit-error, "$rhythm-unit must be `px`, `em` or `rem`.");
  }
  @return null;
}

// Calculate rhythm units.
@function rhythm($lines: 1, $font-size: $rhythm-base-font-size, $offset: 0) {

  @if type-of($lines) != number {
    $lines: rhythm-parse-value-filter($lines);
  }
  $rhythm: convert-length($lines * $rhythm-base-line-height - $offset, $rhythm-unit, $font-size);
  @if unit($rhythm) == px {
    $rhythm: floor($rhythm);
  }
  @return $rhythm;
}

// Calculate the minimum multiple of rhythm units needed to contain the font-size.
@function rhythm-lines-for-font-size($font-size) {
  $lines: if($rhythm-round-to-nearest-half-line,
             ceil(2 * $font-size / $rhythm-base-line-height) / 2,
             ceil($font-size / $rhythm-base-line-height));
  // If lines are cramped include some extra lead.

  @if ($lines * $rhythm-base-line-height - $font-size) < ($rhythm-min-line-leading * 2) {
    $lines: $lines + if($rhythm-round-to-nearest-half-line, 0.5, 1);
  }
  @return $lines;
}

@function rhythm-process-base-values($font-size, $line-height) {
  // Error if invalid
  $is-valid: rhythm-validate($font-size, $line-height);
  @if $rhythm-relative-font-sizing {
    // Adjust font size if base font-size different from default browser (16px)
    $font-size:  100% * ($font-size / $rhythm-browser-default-font-size);
    // Use ems instead of rems to avoid Webkit bug. Usage of rems is uneffected as they will use the
    // em value of the html element.
    $line-height: rhythm-convert-length($line-height, em);
  } @else {
    // ( Use given font-size )
    $line-height: round(line-height);
  }
  @return ($font-size $line-height);
}
// Convert any CSS <length> or <percentage> value to any another.
//
// @param $length
//   A css <length> or <percentage> value
//
// @param $to-unit
//   String matching a css unit keyword, e.g. 'em', '%', etc.
//
// @param $from-context
//   When converting from relative units, the absolute length (in px) to
//   which $length refers (e.g. for $lengths in em units, would normally be the
//   font-size of the current element).
//
// @param $to-context
//   For converting to relative units, the absolute length in px to which the
//   output value will refer. Defaults to the same as $from-context, since it is
//   rarely needed.
@function rhythm-convert-length(
  $length,
  $to-unit,
  $from-context: $rhythm-base-font-size,
  $to-context: $from-context
  ) {
 
  $from-unit: unit($length);
 
  // Optimize for cases where `from` and `to` units are accidentally the same.
  @if $from-unit == $to-unit { @return $length; }
 
  // Context values must be in px so we can determine a conversion ratio for
  // relative units.
  @if unit($from-context) != 'px' {
    $error: rhythm-throw-error($rhythm-invalid-unit-error, "Parameter $from-context must resolve to a value in pixel units.");
  }
  @if unit($to-context) != 'px' {
    $error: rhythm-throw-error($rhythm-invalid-unit-error, "Parameter $to-context must resolve to a value in pixel units.");
  }
 
  // Convert input length to pixels
  $px-length: $length;
 
  @if $from-unit != 'px' {
    // Convert relative units using the from-context parameter.
    @if      $from-unit == 'em'  { $px-length: $length * $from-context / 1em }
    @else if $from-unit == 'rem' { $px-length: $length * $base-font-size / 1rem }
    @else if $from-unit == '%'   { $px-length: $length * $from-context / 100% }
    @else if $from-unit == 'ex'  { $px-length: $length * $from-context / 2ex }
    @else {
      $error: rhythm-throw-error($rhythm-invalid-unit-error, "#{$from-unit} unit not supported");
      @return $length;
    }
  }
 
  // Convert length in pixels to the output unit
  $output-length: $px-length;
  @if $to-unit != 'px' {
    // Relative units
    @if      $to-unit == 'em'  { $output-length: $px-length * 1em / $to-context }
    @else if $to-unit == 'rem' { $output-length: $px-length * 1rem / $base-font-size }
    @else if $to-unit == '%'   { $output-length: $px-length * 100% / $to-context }
    @else if $to-unit == 'ex'  { $output-length: $px-length * 2ex / $to-context }
    @else {
      $error: rhythm-throw-error($rhythm-invalid-unit-error, "#{$to-unit} unit not supported");
    }
  }
 
  @return $output-length;
}

// API
// -------------------------------------------------------------------------------------------------

// @private Outputs rhythm values. For rem units, outputs pixel fallbacks
// by default.
@mixin render-rhythm($property, $values) {
  $output: ();
  @each $value in $values {
    @if unit($value) == px {
      // Ensure all pixel values are rounded to the nearest pixel.
      $output: join($output, round($value));
    }
    @else {
      $output: join($output, $value);
    }
  }
  #{$property}: $output;
}

@mixin rhythm-establish($font-size: $rhythm-base-font-size, $line-height: $rhythm-base-line-height) {
  $processed-values: rhythm-process-base-values($font-size, $line-height);

  // Render HTML element
  html {
      font-size: nth($processed-values, 1);
      line-height: nth($processed-values, 2);
  }
}


@include rhythm-establish($font-size: );

SassMeister-output.css

Invalid CSS after "...sh($font-size: ": expected mixin argument, was ");"