Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.2.5)
// ----

/// this overrides the default fonts directory. Set 
/// it to the location of your fonts.
$fonts-dir: '/fonts';

$fontsMap: (
  "Proxima-Nova": (
    "Proxima-Nova-Light-File": (
      weight: 300
    ),
    "Proxima-Nova-Italic-File": (
      style: italic
    ),
    "Proxima-Nova-Regular-File": null
    )
);
/// Generate the CSS for @font-face rules. This mixin shouldn't be
/// called directly. You should use the buildFontFace mixin instead.
/// @param {String} $fontName - Group name the font will belong to
/// @param {String} $fontFile - filename of the font minus the extension
/// @param {String} $weight [normal] - font-weight
/// @param {String} $style [normal] - font-style
///
/// @access private
/// @author Michael Turnwall
@mixin _fontFace($fontName, $fontFile, $weight: normal, $style: normal) {
    /// This is the directory where the fonts live. You can override this directory by declaring
    /// your own `$fonts-dir` variable globally.
    $fonts-dir: '/fonts' !default;
    @font-face {
        font-family: "#{$fontName}";
        src: url("#{$fonts-dir}/#{$fontFile}.eot");
        src: url("#{$fonts-dir}/#{$fontFile}.eot?#iefix") format("embedded-opentype"),
             url("#{$fonts-dir}/#{$fontFile}.woff") format("woff"),
             url("#{$fonts-dir}/#{$fontFile}.ttf") format("truetype");
        font-weight: $weight;
        font-style: $style;
    }
}

///
/// Use this mixin to build our your custom font families using @font-face. You can
/// either call this mixin individually or pass it a Map. This way you can control your
/// font family groups using a map which is much easier to read and maintain.
///
/// The default font directory is `/fonts`. You can override this value by creating a variable
/// called `$fonts-dir` and setting it's value to where your fonts live.
///
/// @param {String} $fontName - Group name that the font will belong to
/// @param {String | Map} $font - this is the font name minus the file extenstion.
///                                 It can be either just a string of the name or
///                                 a map that contains the font weight and style.
/// @param {String} $weight [normal] - the font-weight value
/// @param {String} $style [normal] - the font-style value
/// @require {Mixin} _fontFace
/// @example scss
///     // Here is how the map should be setup.
///     // If you don't want to pass weight or style just set the value as null
///     $fontsMap: (
///         "Proxima-Nova": (
///             "Proxima-Nova-Light-File": (
///                 weight: 300
///             ),
///             "Proxima-Nova-Italic-File": (
///                 style: italic
///             ),
///             "Proxima-Nova-Regular-File": null
///         )
///     );
///
///     // You can also call it by passing a single font
///     @include buildFontFace("Proxima-Nova", "Proxima-Nova-Light-File", $weight: 300);
///
/// @author Michael Turnwall
@mixin buildFontFace($fontName, $font, $weight: normal, $style: normal) {
    @if type-of($font) == map {
        @if map-has-key($fontsMap, $fontName) {
            @each $fontFile, $map in $font {
                @if type-of($map) == map {
                    @if map-has-key($map, weight) {
                        $weight: map-get($map, weight);
                    }
                    @if map-has-key($map, style) {
                        $style: map-get($map, style);
                    }
                }
                @include _fontFace($fontName, $fontFile, $weight, $style);
                $weight: normal;
                $style: normal;
            }
        }
    } @else {
        @include _fontFace($fontName, $font, $weight, $style);
    }
}
@each $fontName, $list in $fontsMap {
    @include buildFontFace($fontName, $list);
}
@include buildFontFace("Proxima-Nova", "Proxima-Nova-Light-File", $weight: 300);

SassMeister-output.css

@font-face {
  font-family: "Proxima-Nova";
  src: url("/fonts/Proxima-Nova-Light-File.eot");
  src: url("/fonts/Proxima-Nova-Light-File.eot?#iefix") format("embedded-opentype"), url("/fonts/Proxima-Nova-Light-File.woff") format("woff"), url("/fonts/Proxima-Nova-Light-File.ttf") format("truetype");
  font-weight: 300;
  font-style: normal;
}

@font-face {
  font-family: "Proxima-Nova";
  src: url("/fonts/Proxima-Nova-Italic-File.eot");
  src: url("/fonts/Proxima-Nova-Italic-File.eot?#iefix") format("embedded-opentype"), url("/fonts/Proxima-Nova-Italic-File.woff") format("woff"), url("/fonts/Proxima-Nova-Italic-File.ttf") format("truetype");
  font-weight: normal;
  font-style: italic;
}

@font-face {
  font-family: "Proxima-Nova";
  src: url("/fonts/Proxima-Nova-Regular-File.eot");
  src: url("/fonts/Proxima-Nova-Regular-File.eot?#iefix") format("embedded-opentype"), url("/fonts/Proxima-Nova-Regular-File.woff") format("woff"), url("/fonts/Proxima-Nova-Regular-File.ttf") format("truetype");
  font-weight: normal;
  font-style: normal;
}

@font-face {
  font-family: "Proxima-Nova";
  src: url("/fonts/Proxima-Nova-Light-File.eot");
  src: url("/fonts/Proxima-Nova-Light-File.eot?#iefix") format("embedded-opentype"), url("/fonts/Proxima-Nova-Light-File.woff") format("woff"), url("/fonts/Proxima-Nova-Light-File.ttf") format("truetype");
  font-weight: 300;
  font-style: normal;
}