diff --git a/src/plainui/styles/_variables-hub.scss b/src/plainui/styles/_variables-hub.scss
index f0343565417cbcddd29b0c0c94382a3b3edb1624..98d5265d086d6009778d0803a8b0e2bf36ac5da8 100644
--- a/src/plainui/styles/_variables-hub.scss
+++ b/src/plainui/styles/_variables-hub.scss
@@ -103,6 +103,7 @@ $hub-tag-user-color: $black !default;
 
 $hub-main-nav-category-font-weight: 300 !default;
 $hub-main-nav-bg: $body-bg-dark !default;
+$hub-main-nav-bg-mobile: $body-bg-dark !default;
 
 /* Lists*/
 
diff --git a/src/plainui/styles/components/_nav.scss b/src/plainui/styles/components/_nav.scss
index 3b907ce02a601be27fc3760f41def079af4cd917..25a9e8c5180db9344766c4ed7f1e292de6846681 100644
--- a/src/plainui/styles/components/_nav.scss
+++ b/src/plainui/styles/components/_nav.scss
@@ -1,5 +1,5 @@
 .hub-main-navbar {
-  background-color: $hub-main-nav-bg;
+  background-color: $hub-main-nav-bg-mobile;
   display: flex;
   flex-direction: column;
   height: 100vh;
@@ -11,6 +11,12 @@
   z-index: 1000;
 }
 
+@include media-breakpoint-up(md) {
+  .hub-main-navbar {
+    background-color: $hub-main-nav-bg;
+  }
+}
+
 .hub-main-navbar-items {
   padding-bottom: 4rem;
 }
diff --git a/src/plainui/styles/themes/38c3/_38c3-variables.scss b/src/plainui/styles/themes/38c3/_38c3-variables.scss
index f2e95dc19092b9603a7477baf94fbdc4bb3b23ba..75944406439d3bb576540b8671f57a2a52f80a9e 100644
--- a/src/plainui/styles/themes/38c3/_38c3-variables.scss
+++ b/src/plainui/styles/themes/38c3/_38c3-variables.scss
@@ -10,7 +10,8 @@ $hub-event-list-now-color: $black;
 $hub-head-page-font: 400 40px "Space Grotesk";
 $hub-head-page-color: $primary;
 
-$hub-main-nav-bg: "transparent";
+$hub-main-nav-bg: transparent;
+$hub-main-nav-bg-mobile: black;
 $hub-main-nav-category-font-weight: normal;
 
 $hub-head-category-font: 400 22px "Space Grotesk";