Remove bottom border from header

app/assets/stylesheets/framework/header.scss

@@ -4,7 +4,6 @@
   margin-bottom: 0;
   min-height: $header-height;
   border: 0;
-  border-bottom: 1px solid $border-color;
   position: fixed;
   top: 0;
   left: 0;

app/assets/stylesheets/startup/startup-dark.scss

@@ -1031,6 +1031,7 @@ body.gl-dark .logo-text svg {
 }
 body.gl-dark .navbar-gitlab {
   background-color: #2e2e2e;
+  box-shadow: 0 1px 0 0 var(--gray-100);
 }
 body.gl-dark .navbar-gitlab .navbar-sub-nav li.active > a,
 body.gl-dark .navbar-gitlab .navbar-sub-nav li.active > button,

app/assets/stylesheets/themes/theme_light.scss

@@ -89,6 +89,7 @@ body {
 
     .navbar-gitlab {
       background-color: var(--gray-50);
+      box-shadow: 0 1px 0 0 var(--gray-100);
 
       .navbar-sub-nav,
       .navbar-nav {

changelogs/unreleased/mvanremmerden-master-patch-50309.yml

+---
+title: Remove bottom border from header
+merge_request: 56315
+author:
+type: other