diff --git a/dist-electron/main.js b/dist-electron/main.js
index 0a11466..a717c0e 100644
--- a/dist-electron/main.js
+++ b/dist-electron/main.js
@@ -3,9 +3,9 @@ import "node:fs";
 import "node:url";
 import "electron";
 import "module";
-import { M as i, R as _, V as D } from "./main-D2zg5g4b.js";
+import { M, R, V } from "./main-CzLorSzc.js";
 export {
-  i as MAIN_DIST,
-  _ as RENDERER_DIST,
-  D as VITE_DEV_SERVER_URL
+  M as MAIN_DIST,
+  R as RENDERER_DIST,
+  V as VITE_DEV_SERVER_URL
 };
diff --git a/dist-electron/preload.mjs b/dist-electron/preload.mjs
index b05ec55..0c7f825 100644
--- a/dist-electron/preload.mjs
+++ b/dist-electron/preload.mjs
@@ -1 +1,31 @@
-"use strict";const n=require("electron");n.contextBridge.exposeInMainWorld("ipcRenderer",{on(...e){const[r,i]=e;return n.ipcRenderer.on(r,(o,...t)=>i(o,...t))},off(...e){const[r,...i]=e;return n.ipcRenderer.off(r,...i)},send(...e){const[r,...i]=e;return n.ipcRenderer.send(r,...i)},invoke(...e){const[r,...i]=e;return n.ipcRenderer.invoke(r,...i)}});n.contextBridge.exposeInMainWorld("api",{generate:e=>n.ipcRenderer.invoke("generate",e),hanSpell:e=>n.ipcRenderer.invoke("hanSpell-check",e),onNavigate:e=>n.ipcRenderer.invoke("navigate",e),openSetting:()=>n.ipcRenderer.invoke("setting-open"),getAppVersion:()=>n.ipcRenderer.invoke("get-app-version")});n.contextBridge.exposeInMainWorld("theme",{changeTheme:e=>n.ipcRenderer.invoke("theme-mode",e),getTheme:()=>n.ipcRenderer.invoke("get-theme")});
+"use strict";
+const electron = require("electron");
+electron.contextBridge.exposeInMainWorld("ipcRenderer", {
+  on(...args) {
+    const [channel, listener] = args;
+    return electron.ipcRenderer.on(channel, (event, ...args2) => listener(event, ...args2));
+  },
+  off(...args) {
+    const [channel, ...omit] = args;
+    return electron.ipcRenderer.off(channel, ...omit);
+  },
+  send(...args) {
+    const [channel, ...omit] = args;
+    return electron.ipcRenderer.send(channel, ...omit);
+  },
+  invoke(...args) {
+    const [channel, ...omit] = args;
+    return electron.ipcRenderer.invoke(channel, ...omit);
+  }
+});
+electron.contextBridge.exposeInMainWorld("api", {
+  generate: (opts) => electron.ipcRenderer.invoke("generate", opts),
+  hanSpell: (opts) => electron.ipcRenderer.invoke("hanSpell-check", opts),
+  onNavigate: (path, payload) => electron.ipcRenderer.invoke("navigate", path, payload),
+  openSetting: () => electron.ipcRenderer.invoke("setting-open"),
+  getAppVersion: () => electron.ipcRenderer.invoke("get-app-version")
+});
+electron.contextBridge.exposeInMainWorld("theme", {
+  changeTheme: (mode) => electron.ipcRenderer.invoke("theme-mode", mode),
+  getTheme: () => electron.ipcRenderer.invoke("get-theme")
+});
diff --git a/electron/controller/navigate.ts b/electron/controller/navigate.ts
index 1de4d1d..59e5d69 100644
--- a/electron/controller/navigate.ts
+++ b/electron/controller/navigate.ts
@@ -4,18 +4,24 @@ import { quickWin } from '../windows/quickWindow';
 import { RENDERER_DIST, VITE_DEV_SERVER_URL } from '../main';
 import { PRELOAD_PATH } from '../paths';
 
-export const handleNavigate = (_event: unknown, path: string) => {
+export const handleNavigate = (_event: unknown, path: string, payload?: string) => {
   quickWin?.destroy();
 
   if (mainWin && !mainWin.isDestroyed()) {
     mainWin.focus();
     mainWin.webContents.send('navigate-to', path);
+    if (payload) {
+      mainWin.webContents.send('set-spell-from-quick-window', payload);
+    }
     return { ok: true };
   }
 
   createMainWindow(RENDERER_DIST, VITE_DEV_SERVER_URL, PRELOAD_PATH);
   mainWin?.webContents.once('did-finish-load', () => {
     mainWin?.webContents.send('navigate-to', path);
+    if (payload) {
+      mainWin?.webContents.send('set-spell-from-quick-window', payload);
+    }
   });
   mainWin?.show();
   mainWin?.focus();
diff --git a/electron/preload.ts b/electron/preload.ts
index 89a1ae5..0b6f755 100644
--- a/electron/preload.ts
+++ b/electron/preload.ts
@@ -6,7 +6,7 @@ declare global {
     api: {
       generate: (opts: { sentence: string }) => Promise<SpellCheckerApiResponse>;
       hanSpell: (opts: { sentence: string; weakOpt?: number }) => Promise<SpellCheckerApiResponse>;
-      onNavigate: (path: string) => Promise<void>;
+      onNavigate: (path: string, payload?: string) => Promise<void>;
       openSetting: () => Promise<void>;
       getAppVersion: () => Promise<string>;
     };
@@ -40,7 +40,7 @@ contextBridge.exposeInMainWorld('api', {
   generate: (opts: { sentence: string }) => ipcRenderer.invoke('generate', opts),
   hanSpell: (opts: { sentence: string; weakOpt?: number }) =>
     ipcRenderer.invoke('hanSpell-check', opts),
-  onNavigate: (path: string) => ipcRenderer.invoke('navigate', path),
+  onNavigate: (path: string, payload?: string) => ipcRenderer.invoke('navigate', path, payload),
   openSetting: () => ipcRenderer.invoke('setting-open'),
   getAppVersion: () => ipcRenderer.invoke('get-app-version'),
 });
diff --git a/electron/services/gemini/gemini.ts b/electron/services/gemini/gemini.ts
index 0d4c212..1fcf0ab 100644
--- a/electron/services/gemini/gemini.ts
+++ b/electron/services/gemini/gemini.ts
@@ -5,6 +5,9 @@ import { SpellCheckerApiResponse } from '../schema';
 let ai: ReturnType<typeof createAi> | null = null;
 
 function createAi() {
+  if (!process.env.GEMINI_API_KEY) {
+    throw new Error('GEMINI_API_KEY is not set in environment variables.');
+  }
   return new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
 }
 
@@ -13,43 +16,72 @@ function getAi() {
   return ai;
 }
 
-export async function geminiGenerate(contents: string) {
+const GEN_MODELS = [
+  'gemini-2.5-flash-lite',
+  'gemini-2.5-flash',
+  'gemini-2.0-flash-lite',
+  'gemini-2.0-flash',
+];
+
+async function generateWithSingleModel(
+  modelName: string,
+  contents: string
+): Promise<string | null> {
   const response = await getAi().models.generateContent({
-    model: 'gemini-2.5-flash-lite',
+    model: modelName,
     contents,
   });
 
-  if (!response) return '';
+  if (!response) return null;
   if (typeof response === 'string') return response;
   const maybeText = (response as { text?: unknown }).text;
   if (typeof maybeText === 'string') return maybeText;
   try {
     return JSON.stringify(response);
-  } catch (err) {
-    return String(response);
+  } catch {
+    return null;
   }
 }
 
+export async function geminiGenerate(contents: string): Promise<string> {
+  let lastError: unknown = null;
+
+  for (const modelName of GEN_MODELS) {
+    try {
+      const result = await generateWithSingleModel(modelName, contents);
+
+      if (result) return result;
+    } catch (error) {
+      console.warn(`Model [${modelName}] failed. Reason:`, error);
+      lastError = error;
+    }
+  }
+  throw lastError || new Error('All models failed silently.');
+}
+
 export async function checkSpelling(text: string): Promise<SpellCheckerApiResponse | null> {
   const prompt = getSpellCheckPrompt(text);
 
   try {
     const raw = await geminiGenerate(prompt);
-    if (!raw) return null;
 
     const firstBrace = raw.indexOf('{');
     const lastBrace = raw.lastIndexOf('}');
-    const candidate =
-      firstBrace !== -1 && lastBrace !== -1 ? raw.slice(firstBrace, lastBrace + 1) : raw;
 
+    if (firstBrace === -1 || lastBrace === -1) {
+      return null;
+    }
+
+    const candidate = raw.slice(firstBrace, lastBrace + 1);
     const resultObject = JSON.parse(candidate);
-    if (!resultObject) {
-      console.warn('LLM 반환값이 예상 스키마를 따르지 않습니다.', resultObject);
+
+    if (!resultObject || typeof resultObject !== 'object') {
       return null;
     }
+
     return resultObject as unknown as SpellCheckerApiResponse;
   } catch (error) {
-    console.error('LLM 응답 파싱 오류:', error);
-    throw new Error('LLM 응답 파싱 오류');
+    console.error('Spelling check process failed:', error);
+    throw error;
   }
 }
diff --git a/package.json b/package.json
index a31eefc..e8e0bd7 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "matmal",
   "private": true,
-  "version": "0.0.6",
+  "version": "0.0.7",
   "productName": "matmal",
   "description": "간편한 한국어 맞춤법 검사 데스크탑 앱",
   "author": "zzzryt <jinjinstar3@gmail.com>",
diff --git a/src/App.tsx b/src/App.tsx
index 8726af6..804d9c8 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -6,9 +6,19 @@ import { ToastContainer } from 'react-toastify';
 import { useSpellCheck } from './shared/stores/spell';
 
 function App() {
+  const { setSpell } = useSpellCheck();
+
   useEffect(() => {
-    useSpellCheck.getState().setSpell('');
-  }, []);
+    const handleSetSpell = (_event: unknown, text: string) => {
+      setSpell(text);
+    };
+
+    window.ipcRenderer.on('set-spell-from-quick-window', handleSetSpell);
+
+    return () => {
+      window.ipcRenderer.off('set-spell-from-quick-window', handleSetSpell);
+    };
+  }, [setSpell]);
 
   return (
     <>
diff --git a/src/apps/UserInput/index.tsx b/src/apps/UserInput/index.tsx
index 65d1375..9dd7b8c 100644
--- a/src/apps/UserInput/index.tsx
+++ b/src/apps/UserInput/index.tsx
@@ -3,30 +3,49 @@ import Button from '../../shared/components/ui/Button';
 import { useStore } from 'zustand';
 import { useSpellCheck } from '../../shared/stores/spell';
 import { toast } from 'react-toastify';
+import clsx from 'clsx';
+
+const TEXT_LIMIT = 500;
 
 function UserInput() {
   const navigate = useNavigate();
   const { spell, setSpell } = useStore(useSpellCheck);
 
-  const handleSpellingStart = () => {
-    if (spell.length <= 0) {
-      toast.error('검사할 항목을 입력해 주세요.');
-      return;
+  const isValidationText = (text: string) => {
+    if (text.length > TEXT_LIMIT) {
+      toast.error(`텍스트는 ${TEXT_LIMIT}자 이내로 입력해 주세요.`);
+      return false;
     }
+    if (text.trim().length === 0) {
+      toast.error('검사할 텍스트를 입력해 주세요.');
+      return false;
+    }
+    return true;
+  };
+
+  const handleSpellingStart = () => {
+    if (!isValidationText(spell)) return;
     setSpell(spell);
     navigate('/result');
   };
 
+  const overTextLimit = clsx({
+    'text-red-600': spell.length > TEXT_LIMIT,
+  });
+
   return (
     <div>
       <div className="mb-4">
-        <label className="block text-sm font-medium text-gray-700 mb-2">검사할 텍스트</label>
+        <label className="block text-sm font-medium text-gray-500 mb-2">검사할 텍스트</label>
         <textarea
-          className="w-full min-h-100 border rounded p-3 resize-y"
+          className="w-full min-h-100 border rounded p-3 resize-y relative"
           value={spell}
           onChange={(e) => setSpell(e.target.value)}
           placeholder="여기에 텍스트를 입력하거나 붙여넣으세요..."
-        />
+        ></textarea>
+        <span className={`flex justify-end ${overTextLimit}`}>
+          글자수 : {spell.length}/{TEXT_LIMIT}
+        </span>
         <div className="mt-2 flex gap-2">
           <Button variant="primary" onClick={handleSpellingStart}>
             검사 실행
diff --git a/src/apps/quick/QuickSpell.tsx b/src/apps/quick/QuickSpell.tsx
index 4891271..08eb005 100644
--- a/src/apps/quick/QuickSpell.tsx
+++ b/src/apps/quick/QuickSpell.tsx
@@ -1,5 +1,4 @@
 import { useEffect, useState, useCallback } from 'react';
-import { useStore } from 'zustand';
 
 import { SpellCheckerApiResponse } from '../../../electron/services/schema';
 
@@ -13,7 +12,7 @@ import Button from '../../shared/components/ui/Button';
 type Status = 'loading' | 'success' | 'error';
 
 function QuickSpell() {
-  const { spell, setSpell, clearSpell } = useStore(useSpellCheck);
+  const { spell, setSpell, clearSpell } = useSpellCheck();
   const [resultData, setResultData] = useState<SpellCheckerApiResponse | null>(null);
   const [status, setStatus] = useState<Status>('loading');
   const [errorMessage, setErrorMessage] = useState<string | null>(null);
@@ -72,7 +71,7 @@ function QuickSpell() {
   };
 
   const handleDetailInfo = () => {
-    window.api.onNavigate('/result');
+    window.api.onNavigate('/result', spell);
   };
 
   const renderContent = () => {
diff --git a/src/apps/spellChecker/components/SpellChecker.tsx b/src/apps/spellChecker/components/SpellChecker.tsx
index e93a783..0df0e4a 100644
--- a/src/apps/spellChecker/components/SpellChecker.tsx
+++ b/src/apps/spellChecker/components/SpellChecker.tsx
@@ -1,5 +1,4 @@
-import { useEffect, useState, useRef, useCallback } from 'react';
-import { useStore } from 'zustand';
+import { useEffect, useState, useCallback } from 'react';
 
 import { SpellCheckerApiResponse } from '../../../../electron/services/schema';
 
@@ -11,34 +10,27 @@ import Button from '../../../shared/components/ui/Button';
 import { useSpellCheck } from '../../../shared/stores/spell';
 import { LoadingSpinner } from '../../../shared/components/ui/Loading';
 
-interface SpellChecker {
-  inputText: string;
-}
-
-function SpellChecker({ inputText }: SpellChecker) {
-  const { spell, setSpell, undo } = useStore(useSpellCheck);
+function SpellChecker() {
+  const { spell, undo } = useSpellCheck();
   const [resultData, setResultData] = useState<SpellCheckerApiResponse | null>(null);
   const [error, setError] = useState<Error | null>(null);
-  const didMountRef = useRef(false);
 
-  const callGenerateSpell = useCallback(
-    async (sentence?: string) => {
-      try {
-        const res = await window.api.generate({ sentence: sentence ?? spell });
-        setResultData(res as SpellCheckerApiResponse);
-        setSpell(inputText);
-      } catch (err) {
-        setError(err as Error);
-      }
-    },
-    [spell, inputText, setSpell]
-  );
+  console.log('spell:', spell);
+
+  const callGenerateSpell = useCallback(async () => {
+    setResultData(null);
+    setError(null);
+    try {
+      const res = await window.api.generate({ sentence: spell });
+      setResultData(res as SpellCheckerApiResponse);
+    } catch (err) {
+      setError(err as Error);
+    }
+  }, [spell]);
 
   useEffect(() => {
-    if (didMountRef.current) return;
-    didMountRef.current = true;
     callGenerateSpell();
-  }, [callGenerateSpell]);
+  }, [spell, callGenerateSpell]);
 
   if (error) {
     throw error;
@@ -69,7 +61,7 @@ function SpellChecker({ inputText }: SpellChecker) {
               if (!resultData) return <p className="text-gray-500">결과가 여기에 표시됩니다.</p>;
               const raw = resultData.PnuErrorWordList?.PnuErrorWord;
               if (raw.length === 0)
-                return <p className="text-gray-500">결과가 여기에 표시됩니다.</p>;
+                return <p className="text-gray-500">검사할 맞춤법이 존재하지 않습니다.</p>;
               return raw.map((word, idx) => {
                 const currentWord = getCandWord(word);
                 if (currentWord !== word.OrgStr) {
diff --git a/src/page/spell-checker/index.tsx b/src/page/spell-checker/index.tsx
index 6fb4d37..d7abd1a 100644
--- a/src/page/spell-checker/index.tsx
+++ b/src/page/spell-checker/index.tsx
@@ -1,20 +1,17 @@
 import { useNavigate } from 'react-router-dom';
-import { useStore } from 'zustand';
-import { useSpellCheck } from '../../shared/stores/spell';
 
 import Button from '../../shared/components/ui/Button';
 import SpellChecker from '../../apps/spellChecker/components/SpellChecker';
 
 function SpellCheckerPage() {
   const navigate = useNavigate();
-  const { spell } = useStore(useSpellCheck);
 
   return (
     <>
       <Button variant="primary" onClick={() => navigate('/')} className="mb-4">
         텍스트 입력하러 가기
       </Button>
-      <SpellChecker inputText={spell} />
+      <SpellChecker />
     </>
   );
 }
diff --git a/src/shared/components/layout/Footer.tsx b/src/shared/components/layout/Footer.tsx
index 867a8a7..5a3e276 100644
--- a/src/shared/components/layout/Footer.tsx
+++ b/src/shared/components/layout/Footer.tsx
@@ -6,13 +6,15 @@ function Footer() {
   return (
     <>
       <footer className="px-4 py-3 bg-white border-t flex items-center justify-between">
-        <div className="flex items-center gap-3">
+        <div className="flex items-center justify-between gap-3 w-full">
           <button
             className="text-sm text-gray-600 hover:underline"
             onClick={() => setShowHelp(true)}
           >
             도움말
           </button>
+          <span className="text-sm text-gray-600">AI 맞춤법 검사는 틀릴 수 있습니다.</span>
+          <div></div>
         </div>
       </footer>
 
@@ -22,10 +24,10 @@ function Footer() {
           onClick={() => setShowHelp(false)}
         >
           <div
-            className="bg-white rounded p-4 w-11/12 md:w-1/2"
+            className="bg-white dark:bg-black rounded p-4 w-11/12 md:w-1/2"
             onClick={(e) => e.stopPropagation()}
           >
-            <div className="flex items-center justify-between">
+            <div className="flex items-center justify-between text-black">
               <h3 className="text-lg font-medium">도움말</h3>
               <button onClick={() => setShowHelp(false)} className="p-1">
                 ✕
@@ -37,6 +39,10 @@ function Footer() {
                 원하는 글자 드레그 후 [ctrl or Command + shift + d] 키를 눌러 quick window를 실행할
                 수 있습니다.
               </li>
+              <li>
+                macOS에서 실행시 복사 기능이 제한될 수 있습니다. 제대로된 동작이 안될경우 [ctrl +
+                C]복사 기능을 누르고, 단축키를 눌러주세요
+              </li>
               <li>에러가 발생한다면 앱을 껐다가 켜 보세요.</li>
             </ul>
           </div>
diff --git a/src/shared/components/ui/Loading.tsx b/src/shared/components/ui/Loading.tsx
index e1e4d83..30f3a37 100644
--- a/src/shared/components/ui/Loading.tsx
+++ b/src/shared/components/ui/Loading.tsx
@@ -12,16 +12,16 @@ export function LoadingSpinner() {
         <path
           d="M32 3C35.8083 3 39.5794 3.75011 43.0978 5.20749C46.6163 6.66488 49.8132 8.80101 52.5061 11.4939C55.199 14.1868 57.3351 17.3837 58.7925 20.9022C60.2499 24.4206 61 28.1917 61 32C61 35.8083 60.2499 39.5794 58.7925 43.0978C57.3351 46.6163 55.199 49.8132 52.5061 52.5061C49.8132 55.199 46.6163 57.3351 43.0978 58.7925C39.5794 60.2499 35.8083 61 32 61C28.1917 61 24.4206 60.2499 20.9022 58.7925C17.3837 57.3351 14.1868 55.199 11.4939 52.5061C8.801 49.8132 6.66487 46.6163 5.20749 43.0978C3.7501 39.5794 3 35.8083 3 32C3 28.1917 3.75011 24.4206 5.2075 20.9022C6.66489 17.3837 8.80101 14.1868 11.4939 11.4939C14.1868 8.80099 17.3838 6.66487 20.9022 5.20749C24.4206 3.7501 28.1917 3 32 3L32 3Z"
           stroke="currentColor"
-          stroke-width="5"
-          stroke-linecap="round"
-          stroke-linejoin="round"
+          strokeWidth="5"
+          strokeLinecap="round"
+          strokeLinejoin="round"
         ></path>
         <path
           d="M32 3C36.5778 3 41.0906 4.08374 45.1692 6.16256C49.2477 8.24138 52.7762 11.2562 55.466 14.9605C58.1558 18.6647 59.9304 22.9531 60.6448 27.4748C61.3591 31.9965 60.9928 36.6232 59.5759 40.9762"
           stroke="currentColor"
-          stroke-width="5"
-          stroke-linecap="round"
-          stroke-linejoin="round"
+          strokeWidth="5"
+          strokeLinecap="round"
+          strokeLinejoin="round"
           className="text-gray-900"
         ></path>
       </svg>