diff --git a/scss/_variables.scss b/scss/_variables.scss
index 3b31dbdaf4d67585a5f64a02bd125f2477130eea..b96e45b0e4bfc27d065a3bc912eb96a99484b42b 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -172,7 +172,7 @@ $blockquote-font-size:        ($font-size-base * 1.25) !default;
 $blockquote-border-color:     $gray-lighter !default;
 
 $hr-border-color:             rgba(0,0,0,.1) !default;
-$hr-border-width:             $border-width;
+$hr-border-width:             $border-width !default;
 
 
 // Components
@@ -212,8 +212,8 @@ $table-border-color:            $gray-lighter !default;
 //
 // For each of Bootstrap's buttons, define text, background and border color.
 
-$btn-padding-x:                  1rem;
-$btn-padding-y:                  .375rem;
+$btn-padding-x:                  1rem !default;
+$btn-padding-y:                  .375rem !default;
 $btn-font-weight:                normal !default;
 
 $btn-primary-color:              #fff !default;
@@ -249,9 +249,9 @@ $btn-padding-x-lg:               1.25rem !default;
 $btn-padding-y-lg:               .75rem !default;
 
 // Allows for customizing button radius independently from global border radius
-$btn-border-radius:              $border-radius;
-$btn-border-radius-lg:           $border-radius-lg;
-$btn-border-radius-sm:           $border-radius-sm;
+$btn-border-radius:              $border-radius !default;
+$btn-border-radius-lg:           $border-radius-lg !default;
+$btn-border-radius-sm:           $border-radius-sm !default;
 
 
 // Forms
@@ -285,7 +285,7 @@ $input-height:                   (($font-size-base * $line-height) + ($input-pad
 $input-height-lg:                (($font-size-lg * $line-height-lg) + ($input-padding-y-lg * 2) + ($border-width * 2)) !default;
 $input-height-sm:                (($font-size-sm * $line-height-sm) + ($input-padding-y-sm * 2) + ($border-width * 2)) !default;
 
-$form-group-margin-bottom:       15px;
+$form-group-margin-bottom:       15px !default;
 
 $input-group-addon-bg:           $gray-lighter !default;
 $input-group-addon-border-color: $input-border !default;
@@ -293,9 +293,9 @@ $input-group-addon-border-color: $input-border !default;
 $cursor-disabled:                not-allowed !default;
 
 // Form validation icons
-$form-icon-success: "data:image/svg+xml;base64,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";
-$form-icon-warning: "data:image/svg+xml;base64,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";
-$form-icon-error: "data:image/svg+xml;base64,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";
+$form-icon-success: "data:image/svg+xml;base64,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" !default;
+$form-icon-warning: "data:image/svg+xml;base64,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" !default;
+$form-icon-error: "data:image/svg+xml;base64,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" !default;
 
 
 // Dropdowns
@@ -341,15 +341,15 @@ $navbar-border-radius:              $border-radius !default;
 $navbar-padding-horizontal:         $spacer !default;
 $navbar-padding-vertical:           ($spacer / 2) !default;
 
-$navbar-dark-color:                 rgba(255,255,255,.5);
-$navbar-dark-hover-color:           rgba(255,255,255,.75);
-$navbar-dark-active-color:          rgba(255,255,255,1);
-$navbar-dark-disabled-color:        rgba(255,255,255,.25);
+$navbar-dark-color:                 rgba(255,255,255,.5) !default;
+$navbar-dark-hover-color:           rgba(255,255,255,.75) !default;
+$navbar-dark-active-color:          rgba(255,255,255,1) !default;
+$navbar-dark-disabled-color:        rgba(255,255,255,.25) !default;
 
-$navbar-light-color:                rgba(0,0,0,.3);
-$navbar-light-hover-color:          rgba(0,0,0,.6);
-$navbar-light-active-color:         rgba(0,0,0,.8);
-$navbar-light-disabled-color:       rgba(0,0,0,.15);
+$navbar-light-color:                rgba(0,0,0,.3) !default;
+$navbar-light-hover-color:          rgba(0,0,0,.6) !default;
+$navbar-light-active-color:         rgba(0,0,0,.8) !default;
+$navbar-light-disabled-color:       rgba(0,0,0,.15) !default;
 
 
 // Navs
@@ -445,12 +445,12 @@ $state-danger-border:            darken($state-danger-bg, 5%) !default;
 
 
 // Cards
-$card-spacer-x:            1.25rem;
-$card-spacer-y:            .75rem;
-$card-border-width:        .0625rem;
-$card-border-radius:       .25rem;
-$card-border-color:        #e5e5e5;
-$card-border-radius-inner: ($card-border-radius - $card-border-width);
+$card-spacer-x:            1.25rem !default;
+$card-spacer-y:            .75rem !default;
+$card-border-width:        .0625rem !default;
+$card-border-radius:       .25rem !default;
+$card-border-color:        #e5e5e5 !default;
+$card-border-radius-inner: ($card-border-radius - $card-border-width) !default;
 
 $card-cap-bg: #f5f5f5;