diff --git a/frontend/src/App.d.ts b/frontend/src/App.d.ts
deleted file mode 100644
index 08238c7..0000000
--- a/frontend/src/App.d.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-import './App.css';
-export declare let UserName: string;
-declare function App(): import("react/jsx-runtime").JSX.Element;
-export default App;
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 79937a0..3713ce9 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -1,10 +1,8 @@
-import { useEffect, useState } from 'react';
+import { useCallback, useEffect, useState } from 'react';
 import './App.css';
 import { generateBoard } from './utils/board';
 import type { Board } from './types/types';
-import { numberOfMine, size, BoardComponent, resetBoardState } from './components/Board';
-import { resetCellState } from "./components/Cell";
-export let UserName = '';
+import { numberOfMine, size, BoardComponent } from './components/Board';
 
 
 function App() {
@@ -19,7 +17,6 @@ function App() {
 
   const startGame = () => {
     if (username.trim() !== '') {
-      UserName = username;
       setStart(Date.now());
       setElapsedTime(0);
       setGameStarted(true);
@@ -29,9 +26,10 @@ function App() {
     }
   };
 
+  const handleGameOver = useCallback(() => setIsGameOver(true), []);
+  const handleGameClear = useCallback(() => setIsGameOver(true), []);
+
   const restartGame = () => {
-    resetCellState();
-    resetBoardState();
     setBoard(generateBoard(size, size, numberOfMine));
     setStart(Date.now());
     setElapsedTime(0);
@@ -125,8 +123,9 @@ function App() {
           board={board}
           setBoard={setBoard}
           flaggingMode={false}
-          onGameOver={() => setIsGameOver(true)}
-          onGameClear={() => setIsGameOver(true)}
+          onGameOver={handleGameOver}
+          onGameClear={handleGameClear}
+          userName={username}
         />
         <button
           onClick={restartGame}
@@ -168,8 +167,9 @@ function App() {
         board={board}
         setBoard={setBoard}
         flaggingMode={flaggingMode}
-        onGameOver={() => setIsGameOver(true)}
-        onGameClear={() => setIsGameOver(true)}
+        onGameOver={handleGameOver}
+        onGameClear={handleGameClear}
+        userName={username}
       />
       <div style={{
           display: "flex",
diff --git a/frontend/src/components/Board.d.ts b/frontend/src/components/Board.d.ts
deleted file mode 100644
index 24b167d..0000000
--- a/frontend/src/components/Board.d.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import React from "react";
-import type { Board } from "../types/types";
-export declare const size = 15;
-export declare const numberOfMine: number;
-export declare let chainedblock: number;
-export declare let firstblock: boolean;
-export declare function resetBoardState(): void;
-interface Props {
-    board: Board;
-    setBoard: React.Dispatch<React.SetStateAction<Board>>;
-}
-export declare const BoardComponent: React.FC<Props>;
-export {};
diff --git a/frontend/src/components/Board.tsx b/frontend/src/components/Board.tsx
index 05a8577..0f09826 100644
--- a/frontend/src/components/Board.tsx
+++ b/frontend/src/components/Board.tsx
@@ -1,17 +1,12 @@
-import React, { useRef, useState } from "react";
+import React, { useCallback, useRef, useState } from "react";
 import type { Board } from "../types/types";
 import { generateBoard } from "../utils/board";
-import {Cell} from "./Cell";
+import { Cell } from "./Cell";
 
 export const size = 15;
 export const numberOfMine = Math.floor(size * size / 10);
-export let chainedblock = 0;
-export let firstblock = false;
 
-export function resetBoardState() {
-    chainedblock = 0;
-    firstblock = false;
-}
+const API_BASE_URL = "https://1r2mypgiag.execute-api.ap-southeast-2.amazonaws.com/prod";
 
 interface Props {
     board: Board;
@@ -19,6 +14,7 @@ interface Props {
     flaggingMode: boolean;
     onGameOver: () => void;
     onGameClear: () => void;
+    userName: string;
 }
 
 const calculateCellSize = () => {
@@ -29,38 +25,58 @@ const calculateCellSize = () => {
 
 const initialCellSize = calculateCellSize();
 
-export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode, onGameOver, onGameClear }) => {
+export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode, onGameOver, onGameClear, userName }) => {
     const [isGameActive, setIsGameActive] = useState(true);
+    const [hasClickedOnce, setHasClickedOnce] = useState(false);
     const startTimeRef = useRef<number>(0);
+    const chainedblockRef = useRef(0);
+    const openedblockRef = useRef(0);
 
-    const handleGameClear = () => {
-        setIsGameActive(false);
-        onGameClear();
-    };
     const handleGameOver = () => {
         setIsGameActive(false);
         onGameOver();
     };
+
+    const handleManualOpen = useCallback(() => {
+        openedblockRef.current++;
+        if (chainedblockRef.current + openedblockRef.current + numberOfMine >= size * size) {
+            const timeTaken = Math.floor((Date.now() - startTimeRef.current) / 1000);
+            setIsGameActive(false);
+            onGameClear();
+            alert("🎊 Game Clear!\n in " + timeTaken + " seconds!");
+            fetch(`${API_BASE_URL}/scores`, {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({
+                    player_name: userName,
+                    time_taken: timeTaken,
+                    blocks: (size * size),
+                }),
+            })
+            .then(res => res.json())
+            .then(data => console.log('Score API response:', data))
+            .catch(err => console.error('API Error:', err));
+        }
+    }, [onGameClear, userName]);
+
     const currentCellSize = initialCellSize;
     const handleClick = (r: number, c: number) => {
         if (!isGameActive) return;
-        if (!firstblock) {
+        if (!hasClickedOnce) {
             let newBoard: Board;
             do {
                 newBoard = generateBoard(size, size, numberOfMine);
             } while (newBoard[r][c].isMine || newBoard[r][c].neighborMines !== 0);
             newBoard[r][c].isOpen = true;
-            firstblock = true;
+            setHasClickedOnce(true);
             startTimeRef.current = Date.now();
-            if (newBoard[r][c].neighborMines === 0) {
-                chainOpen(newBoard, newBoard[r][c]);
-            }
+            chainedblockRef.current += chainOpen(newBoard, newBoard[r][c]);
             setBoard(newBoard);
-        }else{
+        } else {
             const newBoard = board.map((row) => row.map((cell) => ({ ...cell })));
             newBoard[r][c].isOpen = true;
             if (newBoard[r][c].neighborMines === 0 && !newBoard[r][c].isMine) {
-                chainOpen(newBoard, newBoard[r][c]);
+                chainedblockRef.current += chainOpen(newBoard, newBoard[r][c]);
             }
             setBoard(newBoard);
         }
@@ -68,13 +84,11 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
     return (
         <div style={{
             display: "grid",
-            justifyContent: "center", 
+            justifyContent: "center",
             alignContent: "center",
-
-            gridTemplateColumns: `repeat(${size}, ${currentCellSize+5}px)`, 
+            gridTemplateColumns: `repeat(${size}, ${currentCellSize+5}px)`,
             paddingBottom: "50px",
             width: `${(currentCellSize + 5) * size}px`,
-
             borderRadius: "8px",
         }}>
             {board.map((row, r) =>
@@ -84,7 +98,7 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
                         cell={cell}
                         cellSize={currentCellSize}
                         board={board}
-                        startTime={startTimeRef.current}
+                        hasClickedOnce={hasClickedOnce}
                         onClick={(newBoard) => {
                             if (newBoard) {
                                 setBoard(newBoard);
@@ -92,10 +106,10 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
                                 handleClick(r, c);
                             }
                         }}
-                        onGameClear={handleGameClear}
                         onGameOver={handleGameOver}
                         isGameActive={isGameActive}
                         flaggingMode={flaggingMode}
+                        onManualOpen={handleManualOpen}
                     />
                 ))
             )}
@@ -103,23 +117,22 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
     );
 };
 
-
-function chainOpen(board: Board, cell: Board[0][0]): void {
+function chainOpen(board: Board, cell: Board[0][0]): number {
+    let count = 0;
     const move = [-1, 0, 1];
-    for(let i = 0; i < 3; i++){
-        for(let j = 0; j < 3; j++){
-            if(i === 1 && j === 1){
-                continue;
-            }
+    for (let i = 0; i < 3; i++) {
+        for (let j = 0; j < 3; j++) {
+            if (i === 1 && j === 1) continue;
             const nr = cell.row + move[i], nc = cell.col + move[j];
-            if(0 <= nr && nr < board.length && 0 <= nc && nc < board[0].length 
-                && !board[nr][nc].isMine && !board[nr][nc].isOpen){
-                chainedblock++;
+            if (0 <= nr && nr < board.length && 0 <= nc && nc < board[0].length
+                && !board[nr][nc].isMine && !board[nr][nc].isOpen) {
                 board[nr][nc].isOpen = true;
-                if(board[nr][nc].neighborMines === 0) {
-                    chainOpen(board, board[nr][nc]);
+                count++;
+                if (board[nr][nc].neighborMines === 0) {
+                    count += chainOpen(board, board[nr][nc]);
                 }
             }
         }
     }
-}
\ No newline at end of file
+    return count;
+}
diff --git a/frontend/src/components/Cell.d.ts b/frontend/src/components/Cell.d.ts
deleted file mode 100644
index d41e1e8..0000000
--- a/frontend/src/components/Cell.d.ts
+++ /dev/null
@@ -1,16 +0,0 @@
-import React from "react";
-import type { Board, Cell as CellType } from "../types/types";
-export declare let openedblock: number;
-export declare let gameovered: boolean;
-type Props = {
-    cell: CellType;
-    cellSize: number;
-    onClick: (newBoard?: Board) => void;
-    board: Board;
-    startTime: number;
-    onGameClear: () => void;
-    onGameOver: () => void;
-};
-export declare function resetCellState(): void;
-export declare const Cell: React.FC<Props>;
-export {};
diff --git a/frontend/src/components/Cell.tsx b/frontend/src/components/Cell.tsx
index 237cc45..27d6d65 100644
--- a/frontend/src/components/Cell.tsx
+++ b/frontend/src/components/Cell.tsx
@@ -1,28 +1,19 @@
 import React from "react";
-import { UserName } from "../App";
 import type { Board, Cell as CellType} from "../types/types";
-import { size, numberOfMine, chainedblock} from "./Board";
 import { posOfmine } from "../utils/board";
-export let openedblock = 0;
-const API_BASE_URL = "https://1r2mypgiag.execute-api.ap-southeast-2.amazonaws.com/prod";
-
 
 type Props = {
     cell: CellType;
     cellSize: number;
     onClick: (newBoard?: Board) => void;
     board: Board;
-    startTime: number;
-    onGameClear: () => void;
+    hasClickedOnce: boolean;
+    onManualOpen: () => void;
     onGameOver: () => void;
     isGameActive: boolean;
     flaggingMode: boolean;
 };
 
-export function resetCellState() {
-    openedblock = 0;
-}
-
 const getCellText = (cell: CellType): string => {
     let display = "";
     if(cell.isOpen){
@@ -38,7 +29,8 @@ const getCellText = (cell: CellType): string => {
     }
     return display;
 };
-export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, startTime, onGameClear, onGameOver, isGameActive, flaggingMode}) => {
+
+export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, hasClickedOnce, onManualOpen, onGameOver, isGameActive, flaggingMode}) => {
     const handleClick = () => {
         if(!isGameActive) return;
         if(flaggingMode){
@@ -49,7 +41,7 @@ export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, startTim
         }
         if(cell.isOpen) return;
         if(cell.isflagged) return;
-        if(cell.isMine){
+        if(cell.isMine && hasClickedOnce){
             const newBoard = board.map((row) => row.map((c) => ({ ...c })));
             newBoard[cell.row][cell.col].openedMine = true;
             for(const mine of posOfmine){
@@ -62,26 +54,7 @@ export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, startTim
         }
         onClick();
         if(!cell.isOpen){
-            openedblock++;
-            if(!(chainedblock + openedblock + numberOfMine < size * size)){
-                const timeTaken = Math.floor((Date.now() - startTime) / 1000);
-                onGameClear();
-                alert("🎊 Game Clear!\n in "+ timeTaken+" seconds!");
-                fetch(`${API_BASE_URL}/scores`, {
-                    method: 'POST',
-                    headers: {
-                        'Content-Type': 'application/json',
-                    },
-                    body: JSON.stringify({
-                        player_name: UserName,
-                        time_taken: timeTaken,
-                        blocks: (size * size),
-                    }),
-                })
-                .then(res => res.json())
-                .then(data => console.log('Score API response:', data))
-                .catch(err => console.error('API Error:', err));
-            }
+            onManualOpen();
         }
     }
     return (
@@ -101,4 +74,4 @@ export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, startTim
             {getCellText(cell)}
         </button>
     );
-};
\ No newline at end of file
+};
diff --git a/frontend/src/components/timer.d.ts b/frontend/src/components/timer.d.ts
deleted file mode 100644
index 2de6bb2..0000000
--- a/frontend/src/components/timer.d.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-type TimerProps = {
-    start: number;
-    isActive: boolean;
-};
-declare function Timer({ start, isActive }: TimerProps): import("react/jsx-runtime").JSX.Element;
-export default Timer;
diff --git a/frontend/src/main.d.ts b/frontend/src/main.d.ts
deleted file mode 100644
index 3a29aed..0000000
--- a/frontend/src/main.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-import "./index.css";