diff --git a/src/iframe/life-game.js b/src/iframe/life-game.js
index 5cea482..96a318e 100644
--- a/src/iframe/life-game.js
+++ b/src/iframe/life-game.js
@@ -10,7 +10,7 @@ let patternWidth = 0;
 let previewCells = [];
 
 //盤面の大きさ
-let boardSize = 20;
+const boardSize = 20;
 const cellSize = 450 / boardSize;
 
 //セルの色
@@ -89,7 +89,6 @@ function renderBoard() {
               }
             }
             rerender();
-            stop();
           } else {
             window.parent.postMessage(
               {
@@ -105,7 +104,7 @@ function renderBoard() {
         e.preventDefault();
         if (!isPlacingTemplate) {
           isDragging = true;
-          board[i][j] = board[i][j] === 1 ? 0 : 1;
+          board[i][j] = board[i][j] ? 0 : 1;
           dragMode = board[i][j];
           button.style.backgroundColor = board[i][j] ? aliveCellColor : deadCellColor;
         }
@@ -169,14 +168,6 @@ function rerender() {
       if (currentCellColor !== expectedCellColor) {
         button.style.backgroundColor = expectedCellColor;
       }
-
-      // セルサイズの更新
-      const currentCellsize = button.style.width;
-      const expectedCellsize = `${cellSize}px`;
-      if (currentCellsize !== expectedCellsize) {
-        button.style.width = expectedCellsize;
-        button.style.height = expectedCellsize;
-      }
     }
   }
 }
diff --git a/src/lib/assets/life-game-rules/lifespan.js b/src/lib/assets/life-game-rules/lifespan.js
index 1adbad8..8cb95ff 100644
--- a/src/lib/assets/life-game-rules/lifespan.js
+++ b/src/lib/assets/life-game-rules/lifespan.js
@@ -1,6 +1,5 @@
 "use strict";
 
-let timer = "stop";
 let generationFigure = 0;
 let isDragging = false;
 let dragMode = 0; // 1: 黒にする, 0: 白にする
@@ -11,8 +10,8 @@ let patternWidth = 0;
 let previewCells = [];
 
 //変数設定
-let boardSize = 20; //盤面の大きさ(20x20)
-const cellSize = 600 / boardSize; //セルの大きさ(px)
+const boardSize = 20; //盤面の大きさ(20x20)
+const cellSize = 450 / boardSize; //セルの大きさ(px)
 const maxLifespan = 2; // セルの最大寿命
 
 // around: 周囲の生きたセル数, currentLifespan: 現在の寿命
@@ -54,6 +53,14 @@ const table = document.getElementById("game-board");
 
 //盤面をBoardに従って変更する関数達(Boardを変更したら実行する)
 function renderBoard() {
+  // bodyを中央配置に設定
+  document.body.style.display = "flex";
+  document.body.style.justifyContent = "center";
+  document.body.style.alignItems = "center";
+  document.body.style.minHeight = "100vh";
+  document.body.style.margin = "0";
+  document.body.style.padding = "0";
+
   // 初回の盤面生成
   table.innerHTML = "";
   for (let i = 0; i < boardSize; i++) {
@@ -97,7 +104,6 @@ function renderBoard() {
             }
             rerender();
             generationChange(0);
-            stop();
           } else {
             window.parent.postMessage(
               {
@@ -111,16 +117,16 @@ function renderBoard() {
       };
       button.onmousedown = (e) => {
         e.preventDefault();
-        if (timer === "stop" && !isPlacingTemplate) {
+        if (!isPlacingTemplate) {
           isDragging = true;
-          board[i][j] = !board[i][j];
+          board[i][j] = board[i][j] ? 0 : 1;
           dragMode = board[i][j];
           button.lifespan = board[i][j] ? maxLifespan : 0;
           button.style.backgroundColor = getStyle(board[i][j], button.lifespan);
         }
       };
       button.onmouseenter = () => {
-        if (isDragging && timer === "stop" && board[i][j] !== dragMode && !isPlacingTemplate) {
+        if (isDragging && board[i][j] !== dragMode && !isPlacingTemplate) {
           board[i][j] = dragMode;
           button.lifespan = board[i][j] ? maxLifespan : 0;
           button.style.backgroundColor = getStyle(board[i][j], button.lifespan);
@@ -180,14 +186,6 @@ function rerender() {
       if (currentCellColor !== expectedCellColor) {
         button.style.backgroundColor = expectedCellColor;
       }
-
-      // セルサイズの更新
-      const currentCellsize = button.style.width;
-      const expectedCellsize = `${cellSize}px`;
-      if (currentCellsize !== expectedCellsize) {
-        button.style.width = expectedCellsize;
-        button.style.height = expectedCellsize;
-      }
     }
   }
 }
@@ -197,7 +195,6 @@ document.addEventListener("mouseup", () => {
 });
 
 renderBoard();
-progressBoard();
 
 function generationChange(num) {
   //現在の世代を表すgenerationFigureを変更し、文章も変更
@@ -271,14 +268,6 @@ on.progress = () => {
   progressBoard();
 };
 
-on.play = () => {
-  timer = "start";
-};
-
-on.pause = () => {
-  timer = "stop";
-};
-
 on.board_reset = () => {
   //すべて白にBoardを変更
   board = Array.from({ length: boardSize }, () => Array.from({ length: boardSize }, () => 0));
@@ -295,18 +284,8 @@ on.board_randomize = () => {
   generationChange(0);
 };
 
-on.request_sync = () => {
-  window.parent.postMessage(
-    {
-      type: "sync",
-      data: {
-        generationFigure: generationFigure,
-        boardSize: boardSize,
-      },
-    },
-    "*",
-  );
-  console.log("generationFigure:", generationFigure, "boardSize:", boardSize);
+on.get_boardsize = () => {
+  window.parent.postMessage({ type: "get_boardsize", data: boardSize }, "*");
 };
 
 on.place_template = (template) => {
@@ -315,7 +294,6 @@ on.place_template = (template) => {
   patternWidth = patternShape[0].length;
   isPlacingTemplate = true;
   table.style.cursor = "crosshair";
-  stop();
 };
 
 on.save_board = async () => {
@@ -326,5 +304,4 @@ on.apply_board = (newBoard) => {
   board = newBoard;
   renderBoard();
   generationChange(0);
-  stop();
 };
diff --git a/src/lib/assets/life-game-rules/probabilistics.js b/src/lib/assets/life-game-rules/probabilistics.js
index 933dabb..92ff0bb 100644
--- a/src/lib/assets/life-game-rules/probabilistics.js
+++ b/src/lib/assets/life-game-rules/probabilistics.js
@@ -1,6 +1,5 @@
 "use strict";
 
-let timer = "stop";
 let generationFigure = 0;
 let isDragging = false;
 let dragMode = 0; // 1: 黒にする, 0: 白にする
@@ -11,18 +10,18 @@ let patternWidth = 0;
 let previewCells = [];
 
 //変数設定
-let boardSize = 20; //盤面の大きさ(20x20)
-const cellSize = 600 / boardSize; //セルの大きさ(px)
+const boardSize = 20; //盤面の大きさ(20x20)
+const cellSize = 450 / boardSize; //セルの大きさ(px)
 
 // around: 周囲の生きたセル数 self: 自身が生きているかどうか
 function isNextAlive(around, self) {
   // 自身が生きている & 周囲が 2 か 3 で生存 50%の確率でこのルールに従う
   if (self && 2 <= around && around <= 3) {
-    return Math.random() > 0.5 ? self : !self;
+    return Math.random() > 0.5 ? 1 : 0;
   }
   // 自身が生きている & 周囲が2,3以外で死亡 50%の確率でこのルールに従う
   if (self && (around < 2 || around > 3)) {
-    return Math.random() > 0.5 ? !self : self;
+    return Math.random() > 0.5 ? 0 : 1;
   }
   // 自身が死んでいる & 周囲が 3 で誕生 50%の確率でこのルールに従う
   if (!self && around === 3) {
@@ -45,6 +44,14 @@ const table = document.getElementById("game-board");
 
 //盤面をBoardに従って変更する関数達(Boardを変更したら実行する)
 function renderBoard() {
+  // bodyを中央配置に設定
+  document.body.style.display = "flex";
+  document.body.style.justifyContent = "center";
+  document.body.style.alignItems = "center";
+  document.body.style.minHeight = "100vh";
+  document.body.style.margin = "0";
+  document.body.style.padding = "0";
+
   // 初回の盤面生成
   table.innerHTML = "";
   for (let i = 0; i < boardSize; i++) {
@@ -80,7 +87,6 @@ function renderBoard() {
             }
             rerender();
             generationChange(0);
-            stop();
           } else {
             window.parent.postMessage(
               {
@@ -94,15 +100,15 @@ function renderBoard() {
       };
       button.onmousedown = (e) => {
         e.preventDefault();
-        if (timer === "stop" && !isPlacingTemplate) {
+        if (!isPlacingTemplate) {
           isDragging = true;
-          board[i][j] = !board[i][j];
+          board[i][j] = board[i][j] ? 0 : 1;
           dragMode = board[i][j];
           button.style.backgroundColor = board[i][j] ? "black" : "white";
         }
       };
       button.onmouseenter = () => {
-        if (isDragging && timer === "stop" && board[i][j] !== dragMode && !isPlacingTemplate) {
+        if (isDragging && board[i][j] !== dragMode && !isPlacingTemplate) {
           board[i][j] = dragMode;
           button.style.backgroundColor = board[i][j] ? "black" : "white";
         }
@@ -160,14 +166,6 @@ function rerender() {
       if (currentCellColor !== expectedCellColor) {
         button.style.backgroundColor = expectedCellColor;
       }
-
-      // セルサイズの更新
-      const currentCellsize = button.style.width;
-      const expectedCellsize = `${cellSize}px`;
-      if (currentCellsize !== expectedCellsize) {
-        button.style.width = expectedCellsize;
-        button.style.height = expectedCellsize;
-      }
     }
   }
 }
@@ -177,7 +175,6 @@ document.addEventListener("mouseup", () => {
 });
 
 renderBoard();
-progressBoard();
 
 function generationChange(num) {
   //現在の世代を表すgenerationFigureを変更し、文章も変更
@@ -234,14 +231,6 @@ on.progress = () => {
   progressBoard();
 };
 
-on.play = () => {
-  timer = "start";
-};
-
-on.pause = () => {
-  timer = "stop";
-};
-
 on.board_reset = () => {
   //すべて白にBoardを変更
   board = Array.from({ length: boardSize }, () => Array.from({ length: boardSize }, () => 0));
@@ -258,18 +247,8 @@ on.board_randomize = () => {
   generationChange(0);
 };
 
-on.request_sync = () => {
-  window.parent.postMessage(
-    {
-      type: "sync",
-      data: {
-        generationFigure: generationFigure,
-        boardSize: boardSize,
-      },
-    },
-    "*",
-  );
-  console.log("generationFigure:", generationFigure, "boardSize:", boardSize);
+on.get_boardsize = () => {
+  window.parent.postMessage({ type: "get_boardsize", data: boardSize }, "*");
 };
 
 on.place_template = (template) => {
@@ -278,7 +257,6 @@ on.place_template = (template) => {
   patternWidth = patternShape[0].length;
   isPlacingTemplate = true;
   table.style.cursor = "crosshair";
-  stop();
 };
 
 on.save_board = async () => {
@@ -289,5 +267,4 @@ on.apply_board = (newBoard) => {
   board = newBoard;
   renderBoard();
   generationChange(0);
-  stop();
 };