diff --git a/inst/lib/bsw4/dist/simplex/_variables.scss b/inst/lib/bsw4/dist/simplex/_variables.scss
index 9410754..7ad8101 100755
--- a/inst/lib/bsw4/dist/simplex/_variables.scss
+++ b/inst/lib/bsw4/dist/simplex/_variables.scss
@@ -37,9 +37,11 @@ $danger:        $purple !default;
 $light:         $white !default;
 $dark:          $gray-800 !default;
 
+$enable-shadows: true !default;
+
 // Body
 
-$body-bg:                   #fcfcfc !default;
+$body-bg:                   mix($white, $black, 99%) !default;
 
 // Fonts
 
@@ -56,7 +58,7 @@ $dropdown-link-hover-bg:            $primary !default;
 
 $nav-link-padding-y:                .9rem !default;
 $nav-link-disabled-color:           $gray-400 !default;
-$nav-tabs-border-color:             darken(#fff, 6.5%) !default;
+$nav-tabs-border-color:             mix($white, $black, 93.5%) !default;
 
 // Navbar