Fix empty git repo handling logic and fix mobile view (#33101) (#33102)

Backport #33101 and UI fix from main (including #33108)

web_src/css/base.css

@@ -336,8 +336,13 @@ a.label,
   border-color: var(--color-secondary);
 }
 
+.ui.dropdown .menu > .header {
+  text-transform: none; /* reset fomantic's "uppercase" */
+}
+
 .ui.dropdown .menu > .header:not(.ui) {
   color: var(--color-text);
+  font-size: 0.95em; /* reset fomantic's small font-size */
 }
 
 .ui.dropdown .menu > .item {
@@ -691,11 +696,6 @@ input:-webkit-autofill:active,
   box-shadow: 0 6px 18px var(--color-shadow) !important;
 }
 
-.ui.dropdown .menu > .header {
-  font-size: 0.8em;
-  text-transform: none; /* reset fomantic's "uppercase" */
-}
-
 .ui .text.left {
   text-align: left !important;
 }

web_src/css/modules/navbar.css

@@ -66,7 +66,8 @@
     align-items: stretch;
   }
   /* hide all items */
-  #navbar .item {
+  #navbar .navbar-left > .item,
+  #navbar .navbar-right > .item {
     display: none;
   }
   #navbar #navbar-logo {