Refactor HTML and CSS styles

src/assets/css/tailwind.css

@@ -3,6 +3,15 @@
 @tailwind utilities;
 
 @layer components {
+    html {
+        @apply h-full bg-layout;
+    }
+    body {
+        @apply h-full;
+    }
+    #app {
+        @apply h-full;
+    }
     /* NavBar */
     .menu-item {
         @apply w-full text-left block px-4 py-3 text-base text-gray-800;