diff --git a/sass/_config/_variables.scss b/sass/_config/_variables.scss
index 49399f7..c9e1b95 100644
--- a/sass/_config/_variables.scss
+++ b/sass/_config/_variables.scss
@@ -1,6 +1,9 @@
 // Config file and project variables
 
-// breakpoints values
+// ----------------
+// breakpoints zone
+// ----------------
+
 // warning: you should use your own values, regardless of the devices
 // best practise is Mobile First: (min-width: $breakpoint)
 $tiny        : 480px !default; // or 'em' if you prefer, of course
@@ -9,13 +12,17 @@ $medium      : 768px !default;
 $large       : 992px !default;
 $extra-large : 1200px !default;
 
+// ----------
+// fonts zone
+// ----------
+
 // font families
-$font-family-base     : -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; // system font stack
-$font-family-headings  : sans-serif; // font for h1, h2.. h6
-$font-family-monospace : consolas, courier, monospace; // font for code and samples
+$font-family-base     : -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif !default; // system font stack
+$font-family-headings  : sans-serif !default; // font for h1, h2.. h6
+$font-family-monospace : consolas, courier, monospace !default; // font for code and samples
 
 // font sizes (1.6rem value is "16px" equivalent)
-$font-size-base : 1.6rem;
+$font-size-base : 1.6rem !default;
 
 $font-sizes: (
   base: (
@@ -54,9 +61,9 @@ $line-height-base : 1.5 !default;
 $line-height-l    : 1.7 !default;
 
 // default margin-bottom
-$margin-bottom-base     :   1rem !default;
+$margin-bottom-base     : 1rem !default;
 $headings-margin-bottom : $margin-bottom-base /2 !default;
-$paragraph-margin-bottom:   $margin-bottom-base !default;
+$paragraph-margin-bottom: $margin-bottom-base !default;
 
 // font weights
 $weight-light   : 200 !default;
@@ -65,17 +72,18 @@ $weight-regular : 400 !default;
 $weight-medium  : 500 !default;
 $weight-bold    : 700 !default;
 
+// ------------
+// spacing zone
+// ------------
+
 // grid gutters (for .has-gutter-* classes)
 $grid-gutters: (
   '': 1rem,
   '-l': 2rem,
-  '-xl': 4rem )
-!default;
+  '-xl': 4rem
+) !default;
 
-// global border-radius
-$border-radius: 0 !default;
-
-// spacings (choose unit you prefer)
+// spacings
 $tiny-value             : .5rem  !default;
 $tiny-plus-value        : .7rem !default;
 $small-value            : 1rem !default;
@@ -98,6 +106,10 @@ $zindex-modal:         5000 !default;
 $zindex-notification:  6000 !default;
 $zindex-debug:         7000 !default;
 
+// ----------
+// color zone
+// ----------
+
 // color names
 $white    : #fff !default;
 $gray-100 : #f8f9fa !default;
@@ -138,6 +150,13 @@ $link-decoration-hover : underline;
 
 $forms-color     : $gray-800;
 
+// ---------------
+// components zone
+// ---------------
+
+// global border-radius
+$border-radius: 0 !default;
+
 // component: quotes
 $quote-color     : $gray-200;
 
@@ -171,7 +190,7 @@ $variants-list: (
   (danger,     $color-danger,     $white,    none),
   (inverse,    $color-inverse,    $white,    none),
   (ghost,      $color-ghost,      $white,    0 0 0 1px $white inset)
-);
+) !default;
 
 // component: tabs
 $tabs-border            : $gray-200;