Remove line numbers background style

components/Carbon.js

@@ -160,6 +160,11 @@ class Carbon extends React.Component {
               text-shadow: #eee8d5 0 1px;
             }
 
+            #container :global(.CodeMirror-gutters) {
+              background-color: unset;
+              border-right: none;
+            }
+
             #container :global(.CodeMirror__container) {
               min-width: inherit;
               position: relative;

components/Dropdown.js

@@ -60,7 +60,7 @@ class Dropdown extends React.Component {
   render() {
     // find longest list value in number of characters
     const MIN_WIDTH = this.props.list.reduce(
-      (max, { name }) => (name.length > max ? name.length : max),
+      (max, { name }) => (name && name.length > max ? name.length : max),
       0
     )
 

lib/constants.js

@@ -5,10 +5,6 @@ export const THEMES = [
     id: '3024-night',
     name: '3024 Night'
   },
-  {
-    id: 'ambiance',
-    name: 'Ambiance'
-  },
   {
     id: 'blackboard',
     name: 'Blackboard'