Basic mobile panel switcher.

src/App.scss

@@ -66,11 +66,6 @@ nav {
     }
 }
 
-.sidebar {
-    flex: 1;
-    flex-basis: 300px;
-}
-
 main-router {
     flex: 1;
 }
@@ -230,3 +225,34 @@ nav {
     flex: 2;
     flex-basis: 500px;
 }
+
+.sidebar {
+    flex: 1;
+    flex-basis: 300px;
+}
+
+.mobile-shown {
+    display: none;
+}
+
+.panel-switcher {
+    display: none;
+    width: 100%;
+
+    button {
+        display: block;
+        flex: 1;
+        margin: 0.5em;
+        padding: 0.5em;
+    }
+}
+
+@media all and (max-width: 959px) {
+    .mobile-hidden {
+        display: none;
+    }
+
+    .panel-switcher {
+        display: flex;
+    }
+}