diff --git a/frontend/package.json b/frontend/package.json
index b4db224..cddb272 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -23,6 +23,7 @@
   },
   "devDependencies": {
     "@codemirror/lang-markdown": "^6.2.5",
+    "@codemirror/theme-one-dark": "^6.1.2",
     "@types/node": "^20.14.0",
     "@vitejs/plugin-vue": "^5.0.5",
     "autoprefixer": "^10.4.19",
diff --git a/frontend/src/components/editor/VisualEditor.vue b/frontend/src/components/editor/VisualEditor.vue
index 2af69f3..a70c6b0 100644
--- a/frontend/src/components/editor/VisualEditor.vue
+++ b/frontend/src/components/editor/VisualEditor.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { watch, onMounted, onBeforeUnmount } from 'vue'
+import { watch, onBeforeUnmount } from 'vue'
 import { useEditor, EditorContent } from '@tiptap/vue-3'
 import StarterKit from '@tiptap/starter-kit'
 import { toTipTap, fromTipTap } from '@/bridge/asciidoc-bridge'
diff --git a/frontend/src/vite-env.d.ts b/frontend/src/vite-env.d.ts
new file mode 100644
index 0000000..11f02fe
--- /dev/null
+++ b/frontend/src/vite-env.d.ts
@@ -0,0 +1 @@
+/// <reference types="vite/client" />