Fixes #8374: ensure navbar is always at least 50px

docs/assets/css/bootstrap.css

@@ -2759,6 +2759,7 @@ button.close {
 
 .navbar {
   position: relative;
+  min-height: 50px;
   padding-right: 15px;
   padding-left: 15px;
   margin-bottom: 20px;

less/navbar.less

@@ -5,6 +5,7 @@
 // Wrapper and base class
 .navbar {
   position: relative;
+  min-height: @navbar-height; // Ensure a navbar always shows (e.g., without a .navbar-brand in collapsed mode)
   margin-bottom: 20px;
   padding-left: @navbar-padding-horizontal;
   padding-right: @navbar-padding-horizontal;