message: fix variables.scss
diff: @@ -161,10 +161,10 @@ $card-padding-y-lg: 20px !default;
  $card-border-radius: $border-radius !default;
  $card-border-color: $border-color !default;
  $card-bordered-color: $primary-color !default;
  -$card-header-bg-color: $white;
  -$card-body-bg-color: $grey-100;
  -$card-footer-bg-color: $white;
  -$card-box-shadow: $box-shadow;
  +$card-header-bg-color: $white !default;
  +$card-body-bg-color: $grey-100 !default;
  +$card-footer-bg-color: $white !default;
  +$card-box-shadow: $box-shadow !default;
  // Collapse
  $collapse-padding-x: 20px !default;
  @@ -177,9 +177,9 @@ $collapse-padding-y-lg: 20px !default;
  $collapse-border-radius: $border-radius !default;
  $collapse-border-color: $border-color !default;
  $collapse-bordered-color: $primary-color !default;
  -$collapse-header-bg-color: $white;
  -$collapse-body-bg-color: $grey-100;
  -$collapse-group-box-shadow: $box-shadow;
  +$collapse-header-bg-color: $white !default;
  +$collapse-body-bg-color: $grey-100 !default;
  +$collapse-group-box-shadow: $box-shadow !default;
  // Links
  //
  @@ -361,7 +361,7 @@ $field-label-color: $text-color !default;
  $field-label-font-size: 12px !default;
  $field-label-font-weight: 400 !default;
  -$field-extra-color: $text-color-secondary;
  +$field-extra-color: $text-color-secondary !default;
  // Input
  $input-padding-y: 6px !default;
  