add sass/scratch.scss and associated sass files

Resources/public/sass/contrib/bourbon/functions/_modular-scale.scss

@@ -0,0 +1,69 @@
+// Scaling Variables
+$golden:           1.618;
+$minor-second:     1.067;
+$major-second:     1.125;
+$minor-third:      1.2;
+$major-third:      1.25;
+$perfect-fourth:   1.333;
+$augmented-fourth: 1.414;
+$perfect-fifth:    1.5;
+$minor-sixth:      1.6;
+$major-sixth:      1.667;
+$minor-seventh:    1.778;
+$major-seventh:    1.875;
+$octave:           2;
+$major-tenth:      2.5;
+$major-eleventh:   2.667;
+$major-twelfth:    3;
+$double-octave:    4;
+
+$modular-scale-ratio: $perfect-fourth !default;
+$modular-scale-base: em($em-base) !default;
+
+@function modular-scale($increment, $value: $modular-scale-base, $ratio: $modular-scale-ratio) {
+  $v1: nth($value, 1);
+  $v2: nth($value, length($value));
+  $value: $v1;
+
+  // scale $v2 to just above $v1
+  @while $v2 > $v1 {
+    $v2: ($v2 / $ratio); // will be off-by-1
+  }
+  @while $v2 < $v1 {
+    $v2: ($v2 * $ratio); // will fix off-by-1
+  }
+
+  // check AFTER scaling $v2 to prevent double-counting corner-case
+  $double-stranded: $v2 > $v1;
+
+  @if $increment > 0 {
+    @for $i from 1 through $increment {
+      @if $double-stranded and ($v1 * $ratio) > $v2 {
+        $value: $v2;
+        $v2: ($v2 * $ratio);
+      } @else {
+        $v1: ($v1 * $ratio);
+        $value: $v1;
+      }
+    }
+  }
+
+  @if $increment < 0 {
+    // adjust $v2 to just below $v1
+    @if $double-stranded {
+      $v2: ($v2 / $ratio);
+    }
+
+    @for $i from $increment through -1 {
+      @if $double-stranded and ($v1 / $ratio) < $v2 {
+        $value: $v2;
+        $v2: ($v2 / $ratio);
+      } @else {
+        $v1: ($v1 / $ratio);
+        $value: $v1;
+      }
+    }
+  }
+
+  @return $value;
+}