Show in-app notification when an update is availble

Change-Id: Ia27addc67f70adf654846ef1a0d2bf9bd9d8024f
diff --git a/css/styles.css b/css/styles.css
index d9bf932..435b652 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -94,6 +94,16 @@
   text-decoration: underline;
 }
 
+.update-available {
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  padding: 16px;
+  background: black;
+  color: white;
+}
+
 /* DARK THEME */
 @media screen {
   .dark-theme {
@@ -114,6 +124,11 @@
   .dark-theme .song {
     box-shadow: none;
   }
+
+  .dark-theme .update-available {
+    background: white;
+    color: black;
+  }
 }
 
 @media print {