Nicer color for the app switcher

src/plugins/rootview/styles/app-switcher.scss

@@ -1,8 +1,15 @@
-converse-app-switcher {
-    box-shadow: 0 0 0.3em gray;
-    margin-right: 0.4em;
-    padding: 0.5em;
-    li {
-        margin-bottom: 1em;
+.conversejs {
+    converse-app-switcher {
+        box-shadow: 0 0 0.3em gray;
+        margin-right: 0.4em;
+        padding: 0.5em;
+        li {
+            margin-bottom: 1em;
+        }
+        .nav-link {
+            &.active {
+                background-color: var(--highlight-color-hover) !important;
+            }
+        }
     }
 }