improve scrollbars, add avatar to menu-item since it appears in

autocomplete, add wallpaper color

src/components/menu_item.style.js

@@ -7,7 +7,8 @@ export default {
     'Input',
     'Border',
     'ButtonUnstyled',
-    'Badge'
+    'Badge',
+    'Avatar'
   ],
   states: {
     hover: ':hover',

src/components/root.style.js

@@ -16,7 +16,9 @@ export default {
     {
       directives: {
         '--font': 'generic | sans-serif',
-        '--monoFont': 'generic | monospace'
+        '--monoFont': 'generic | monospace',
+        '--bg': 'color | #000000', // just to establish order
+        '--wallpaper': 'color | --bg, -2'
       }
     }
   ]

src/components/scrollbar.style.js

@@ -4,7 +4,7 @@ export default {
   defaultRules: [
     {
       directives: {
-        background: '--bg'
+        background: '--wallpaper'
       }
     }
   ]