Mixin that uses some Compass functions to fix vertical rhythm based on a fixed height and a font size.

fix-vertical-rhythm.scss

@mixin fix-vertical-rhythm($height, $font-size: $base-font-size, $padding: true) {
  @if $height > 0 {
    $lines: lines-for-font-size($height);
    $offset: rhythm($lines, $font-size, $height) / 2;
    @if $padding {
      padding-top: $offset;
      padding-bottom: $offset;
    }
    @else {
      margin-top: $offset;
      margin-bottom: $offset;
    }
  }
}