Fixes the theme of code block by codemirror

browser/components/MarkdownPreview.js

@@ -186,7 +186,7 @@ export default class MarkdownPreview extends React.Component {
   setCodeTheme (theme) {
     theme = consts.THEMES.some((_theme) => _theme === theme)
       ? theme
-      : 'default'
+      : 'elegant'
     this.getWindow().document.getElementById('codeTheme').href = `${appPath}/node_modules/codemirror/theme/${theme}.css`
   }
 

browser/main/lib/ConfigManager.js

@@ -34,7 +34,7 @@ export const DEFAULT_CONFIG = {
   preview: {
     fontSize: '14',
     fontFamily: 'Lato',
-    codeBlockTheme: 'xcode',
+    codeBlockTheme: 'elegant',
     lineNumber: true
   }
 }