////
/// Copyright (c) 2016 Martin Donath <martin.donath@squidfunk.com>
///
/// Permission is hereby granted, free of charge, to any person obtaining a
/// copy of this software and associated documentation files (the "Software"),
/// to deal in the Software without restriction, including without limitation
/// the rights to use, copy, modify, merge, publish, distribute, sublicense,
/// and/or sell copies of the Software, and to permit persons to whom the
/// Software is furnished to do so, subject to the following conditions:
///
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
/// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
/// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
/// DEALINGS
////

// ----------------------------------------------------------------------------
// Helpers
// ----------------------------------------------------------------------------

///
/// Convert font size in px to em.
///
/// @group  helpers
/// @access public
/// @param  {Number} $size Font size in px
/// @param  {Number} $base Base font size
/// @return {Number}       Font size in em
///
@function px2em($size, $base: 16px) {
  @if unit($size) == px {
    @if unit($base) == px {
      @return ($size / $base) * 1em;
    } @else {
      @error "Invalid base: #{$base} - unit must be 'px'";
    }
  } @else {
    @error "Invalid size: #{$size} - unit must be 'px'";
  }
}