diff --git a/frontend/src/components/Board.tsx b/frontend/src/components/Board.tsx
index 635358c..8208668 100644
--- a/frontend/src/components/Board.tsx
+++ b/frontend/src/components/Board.tsx
@@ -1,4 +1,4 @@
-import React, { useCallback, useRef, useState } from "react";
+import React, { useCallback, useEffect, useRef, useState } from "react";
 import type { Board } from "../types/types";
 import { generateBoard } from "../utils/board";
 import { Cell } from "./Cell";
@@ -23,15 +23,20 @@ const calculateCellSize = () => {
     return Math.floor((containerSize - safePadding) / size);
 };
 
-const initialCellSize = calculateCellSize();
-
 export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode, onGameOver, onGameClear, userName }) => {
     const [isGameActive, setIsGameActive] = useState(true);
     const [hasClickedOnce, setHasClickedOnce] = useState(false);
+    const [cellSize, setCellSize] = useState(calculateCellSize);
     const startTimeRef = useRef<number>(0);
     const chainedblockRef = useRef(0);
     const openedblockRef = useRef(0);
 
+    useEffect(() => {
+        const handleResize = () => setCellSize(calculateCellSize());
+        window.addEventListener("resize", handleResize);
+        return () => window.removeEventListener("resize", handleResize);
+    }, []);
+
     const handleGameOver = () => {
         setIsGameActive(false);
         onGameOver();
@@ -58,7 +63,6 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
         }
     }, [onGameClear, userName]);
 
-    const currentCellSize = initialCellSize;
     const handleClick = (r: number, c: number) => {
         if (!isGameActive) return;
         if (!hasClickedOnce) {
@@ -85,9 +89,10 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
             display: "grid",
             justifyContent: "center",
             alignContent: "center",
-            gridTemplateColumns: `repeat(${size}, ${currentCellSize+5}px)`,
-            paddingBottom: "50px",
-            width: `${(currentCellSize + 5) * size}px`,
+            gridTemplateColumns: `repeat(${size}, ${cellSize}px)`,
+            gridTemplateRows: `repeat(${size}, ${cellSize}px)`,
+            border: "1px solid black",
+            width: `${cellSize * size}px`,
             borderRadius: "8px",
         }}>
             {board.map((row, r) =>
@@ -95,7 +100,7 @@ export const BoardComponent: React.FC<Props> = ({ board, setBoard, flaggingMode,
                     <Cell
                         key={`${r}-${c}`}
                         cell={cell}
-                        cellSize={currentCellSize}
+                        cellSize={cellSize}
                         board={board}
                         hasClickedOnce={hasClickedOnce}
                         onClick={(newBoard) => {
diff --git a/frontend/src/components/Cell.tsx b/frontend/src/components/Cell.tsx
index 27d6d65..ca8f7e3 100644
--- a/frontend/src/components/Cell.tsx
+++ b/frontend/src/components/Cell.tsx
@@ -63,8 +63,11 @@ export const Cell: React.FC<Props> = ({ cell, cellSize, onClick, board, hasClick
             style={{
                 width: cellSize,
                 height: cellSize,
-                border: "1px solid #666",
+                padding: 0,
+                margin: 0,
+                border: "1px solid black",
                 background: cell.isOpen ? "#ddd" : "#999",
+                color: "black",
                 fontSize: `${cellSize * 0.5}px`,
                 justifyContent: "center",
                 alignItems: "center",
diff --git a/frontend/src/components/timer.tsx b/frontend/src/components/timer.tsx
deleted file mode 100644
index be89399..0000000
--- a/frontend/src/components/timer.tsx
+++ /dev/null
@@ -1,34 +0,0 @@
-import { useState, useEffect } from "react";
-
-type TimerProps = {
-    start: number;
-    isActive: boolean;
-};
-
-function Timer({ start, isActive }: TimerProps) {
-    const [elapsedTime, setElapsedTime] = useState(0);
-
-    useEffect(() => {
-        if (!isActive) return;
-        const timer = setInterval(() => {
-            setElapsedTime(Math.floor((Date.now() - start) / 1000));
-        }, 1000);
-
-        return () => clearInterval(timer);
-    }, [start, isActive]);
-
-    const hours = Math.floor(elapsedTime / 3600);
-    const minutes = Math.floor((elapsedTime % 3600) / 60);
-    const seconds = elapsedTime % 60;
-    const format = (num: number) => String(num).padStart(2, '0');
-
-    return (
-        <h2>
-            {`⏰`}
-            {hours > 0 ? `${format(hours)}:` : ''}
-            {format(minutes)}:{format(seconds)}
-        </h2>
-    );
-}
-
-export default Timer;
\ No newline at end of file