diff --git a/backend/index.js b/backend/index.js
index 6f70e8e..ca75dc1 100644
--- a/backend/index.js
+++ b/backend/index.js
@@ -40,6 +40,10 @@ const PORT = process.env.PORT || 4000;
 const games = [];
 // map socket.id -> { gameId, playerId }
 const socketMap = new Map();
+// map `${gameId}:${playerId}` -> timeoutId for pending disconnects
+const pendingDisconnects = new Map();
+
+function pdKey(gameId, playerId){ return `${gameId}:${playerId}`; }
 
 app.post('/api/create', (req, res) => {
   console.log('[backend] POST /api/create received', req.body && { name: req.body.name, owner: req.body.ownerNickname });
@@ -171,6 +175,9 @@ app.post('/api/leave', (req, res) => {
   if (g.started) return res.status(403).json({ error: 'game in progress' });
   // remove player (allowed only if game not started)
   const leaving = g.players.splice(pIndex, 1)[0];
+  // clear any pending disconnect timer for this player
+  const key = pdKey(gameId, playerId);
+  if(pendingDisconnects.has(key)){ clearTimeout(pendingDisconnects.get(key)); pendingDisconnects.delete(key); }
   // if the leaving player was the owner, remove the entire game
   if(g.ownerId && leaving.id === g.ownerId){
     games.splice(gIndex, 1);
@@ -284,6 +291,18 @@ io.on('connection', (socket) => {
       if(gameId && playerId){
         socketMap.set(socket.id, { gameId, playerId });
         log('identify', { socketId: socket.id, gameId, playerId });
+        // if this player had a pending disconnect timer, cancel it and mark reconnected
+        const key = pdKey(gameId, playerId);
+        if(pendingDisconnects.has(key)){
+          clearTimeout(pendingDisconnects.get(key));
+          pendingDisconnects.delete(key);
+          // mark player as connected again and notify others
+          const g = games.find(x => x.id === gameId);
+          if(g){
+            const p = g.players.find(p => p.id === playerId);
+            if(p){ p.connected = true; io.to(gameId).emit('player-update', g); io.emit('games-list', games); }
+          }
+        }
       }
     }catch(e){ }
   });
@@ -348,33 +367,38 @@ io.on('connection', (socket) => {
     log('socket disconnect', { socketId: socket.id, reason, meta });
     if(!meta) return;
     const { gameId, playerId } = meta;
+    // remove mapping for this socket immediately
     socketMap.delete(socket.id);
-    const gIndex = games.findIndex(x => x.id === gameId);
-    if(gIndex === -1) return;
-    const g = games[gIndex];
-    const pIndex = g.players.findIndex(p => p.id === playerId);
-    if(pIndex === -1) return;
-    const player = g.players[pIndex];
-    // mark as disconnected instead of removing when game started
-    if (g.started) {
-      player.connected = false;
-      console.log(`socket ${socket.id} disconnected (${reason}), marked player ${player.id} disconnected in ${gameId}`);
+    // schedule a delayed removal: if the player doesn't reconnect within 3s, consider them left
+    const key = pdKey(gameId, playerId);
+    if(pendingDisconnects.has(key)){
+      clearTimeout(pendingDisconnects.get(key));
+      pendingDisconnects.delete(key);
+    }
+    const t = setTimeout(() => {
+      // perform removal after grace period
+      const gIndex = games.findIndex(x => x.id === gameId);
+      if(gIndex === -1){ pendingDisconnects.delete(key); return; }
+      const g = games[gIndex];
+      const pIndex = g.players.findIndex(p => p.id === playerId);
+      if(pIndex === -1){ pendingDisconnects.delete(key); return; }
+      const player = g.players[pIndex];
+      // remove player regardless of started state (user asked players away >3s are considered left)
+      const leaving = g.players.splice(pIndex, 1)[0];
+      log('delayed remove player', { gameId, playerId: leaving.id, owner: g.ownerId });
+      // if owner left, remove entire game immediately
+      if(g.ownerId && leaving.id === g.ownerId){
+        games.splice(gIndex, 1);
+        io.emit('games-list', games);
+        io.to(gameId).emit('game-deleted', { gameId });
+        pendingDisconnects.delete(key);
+        return;
+      }
       io.to(gameId).emit('player-update', g);
       io.emit('games-list', games);
-      return;
-    }
-    // if game not started, remove player as before
-    const leaving = g.players.splice(pIndex, 1)[0];
-    console.log(`socket ${socket.id} disconnected (${reason}), removed player ${leaving.id} from ${gameId}`);
-    // if owner left and game not started, delete the game
-    if(g.ownerId && leaving.id === g.ownerId){
-      games.splice(gIndex, 1);
-      io.emit('games-list', games);
-      io.to(gameId).emit('game-deleted', { gameId });
-      return;
-    }
-    io.to(gameId).emit('player-update', g);
-    io.emit('games-list', games);
+      pendingDisconnects.delete(key);
+    }, 3000);
+    pendingDisconnects.set(key, t);
   });
 });
 
diff --git a/frontend/public/game.html b/frontend/public/game.html
index d0b5a5e..8d769f4 100644
--- a/frontend/public/game.html
+++ b/frontend/public/game.html
@@ -11,12 +11,15 @@
     #board-wrapper{width:100%;max-width:900px;margin:0 auto}
     .board{display:grid;border:2px solid #333;box-sizing:border-box}
     .row{display:contents}
-    .cell{position:relative;padding:0;overflow:hidden}
+  .cell{position:relative;padding:0;overflow:hidden;display:flex;align-items:center;justify-content:center}
     .cell .piece{width:100%;height:100%;object-fit:contain;display:block}
     .cell.selected{outline:3px solid rgba(0,128,255,0.6);}
     /* make board square and responsive: use a wrapper with aspect-ratio */
     #board-wrapper .board{width:100%;aspect-ratio:1/1}
     /* grid cells will be created dynamically via JS using grid-template */
+    /* checkerboard colors */
+    .board .cell:nth-child(odd){ background: #f0d9b5; }
+    .board .cell:nth-child(even){ background: #b58863; }
     #meta{margin-top:8px}
   </style>
 </head>
diff --git a/frontend/public/index.html b/frontend/public/index.html
index 97ae4fa..fef348b 100644
--- a/frontend/public/index.html
+++ b/frontend/public/index.html
@@ -45,5 +45,6 @@
   </div>
 
   <script src="src/main.js?v=2"></script>
+  <script src="https://cdn.socket.io/4.5.4/socket.io.min.js"></script>
 </body>
 </html>
diff --git a/frontend/public/src/main.js b/frontend/public/src/main.js
index 8216a6d..01a556c 100644
--- a/frontend/public/src/main.js
+++ b/frontend/public/src/main.js
@@ -75,6 +75,16 @@ function renderGameList(){
     });
 }
 
+// Socket: listen for global games-list updates from backend to refresh lobby list live
+if(typeof io !== 'undefined'){
+  try{
+    const sock = io('http://localhost:4000', { transports: ['websocket', 'polling'] });
+    sock.on('connect', () => { console.log('lobby socket connected', sock.id); });
+    sock.on('games-list', (list) => { console.log('games-list event received', list); try { renderGameList(); } catch(e){} });
+    sock.on('connect_error', (e) => { console.warn('lobby socket connect error', e); });
+  }catch(e){ console.warn('failed to init lobby socket', e); }
+}
+
 function renderGameListItem(ul, g){
   const li = document.createElement('li');
   // display only human-friendly name; avoid showing internal ids
@@ -82,7 +92,18 @@ function renderGameListItem(ul, g){
 
   // detect if this client already joined this game (we store playerId in sessionStorage)
   const storedPlayerId = sessionStorage.getItem(`playerId:${g.id}`);
-  const alreadyJoined = storedPlayerId ? (g.players || []).some(p => p.id === storedPlayerId) : false;
+  // If we have a stored player id but the server-side game no longer contains that player,
+  // cleanup the sessionStorage entry (it means the player was removed / left).
+  let alreadyJoined = false;
+  if (storedPlayerId) {
+    const playerStillInGame = (g.players || []).some(p => p.id === storedPlayerId);
+    if (!playerStillInGame) {
+      // stale stored id: remove it
+      sessionStorage.removeItem(`playerId:${g.id}`);
+    } else {
+      alreadyJoined = true;
+    }
+  }
 
   if(alreadyJoined){
     const span = document.createElement('span');
diff --git a/frontend/public/src/waiting.js b/frontend/public/src/waiting.js
index 75b172d..e17b361 100644
--- a/frontend/public/src/waiting.js
+++ b/frontend/public/src/waiting.js
@@ -79,6 +79,7 @@ function tryConnectSocket(gameId){
     const stored = sessionStorage.getItem(`playerId:${gameId}`) || (()=>{ const all = JSON.parse(localStorage.getItem('games') || '[]'); const g = all.find(x=>x.id===gameId); return g && g.players && g.players[0] && g.players[0].id; })();
     if(stored) sock.emit('identify', { gameId, playerId: stored });
   });
+  sock.on('reconnect', (attempt) => { console.log('waiting socket reconnected', attempt); });
   sock.on('game-deleted', (payload) => {
     if(payload && payload.gameId === gameId){
       sessionStorage.removeItem(`playerId:${gameId}`);
@@ -88,7 +89,10 @@ function tryConnectSocket(gameId){
   });
   sock.on('player-update', (g) => {
     if(!g) return;
+    console.log('[waiting.js] player-update received', g);
     renderWaitingPlayers(g.players||[]);
+    // update start button visibility/disabled state live
+    try { console.log('[waiting.js] updating start button'); updateStartButton(g); } catch(e){ console.error('updateStartButton error', e); }
   });
   sock.on('game-start', (g) => {
     if(!g) return;
@@ -101,6 +105,15 @@ function tryConnectSocket(gameId){
   });
 }
 
+function updateStartButton(g){
+  const stored = sessionStorage.getItem(`playerId:${gameId}`);
+  const ownerId = g.players && g.players[0] && g.players[0].id;
+  const startBtn = q('#start-btn');
+  console.log('[waiting.js] updateStartButton values', { ownerId, stored, playersLength: (g.players||[]).length, startBtnExists: !!startBtn });
+  if(ownerId && stored && ownerId === stored){ startBtn?.classList.remove('hidden'); } else { startBtn?.classList.add('hidden'); }
+  if(startBtn){ startBtn.disabled = ((g.players||[]).length < 2); }
+}
+
 function renderWaitingPlayers(players){
   const ul = q('#wait-players'); ul.innerHTML = '';
   if(!players || players.length === 0) ul.innerHTML = '<li>Aucun joueur</li>';
diff --git a/frontend/src/game.js b/frontend/src/game.js
index 68e1944..ec0b0bc 100644
--- a/frontend/src/game.js
+++ b/frontend/src/game.js
@@ -12,12 +12,22 @@ function renderBoardFromState(state) {
   const boardEl = document.createElement('div');
   boardEl.className = 'board';
 
+  // if no state provided, create an empty 8x8 board
+  if(!state || !state.board){
+    const w = 8, h = 8;
+    const board = Array.from({ length: h }, () => Array.from({ length: w }, () => null));
+    state = { board, width: w, height: h };
+  }
+
   const h = state.height || state.board.length;
   const w = state.width || (state.board[0] && state.board[0].length) || 8;
 
+  // Use CSS grid so cells distribute evenly and keep the board square via wrapper's aspect-ratio
+  boardEl.style.display = 'grid';
+  boardEl.style.gridTemplateColumns = `repeat(${w}, 1fr)`;
+  boardEl.style.gridTemplateRows = `repeat(${h}, 1fr)`;
+
   for (let r = 0; r < h; r++) {
-    const row = document.createElement('div');
-    row.className = 'row';
     for (let c = 0; c < w; c++) {
       const cell = document.createElement('div');
       cell.className = 'cell';
@@ -44,7 +54,7 @@ function renderBoardFromState(state) {
       }
 
       cell.appendChild(piece);
-      row.appendChild(cell);
+      boardEl.appendChild(cell);
       // click to select/move
       cell.addEventListener('click', () => {
         // if no game/socket, ignore
@@ -67,7 +77,6 @@ function renderBoardFromState(state) {
         }
       });
     }
-    boardEl.appendChild(row);
   }
   container.appendChild(boardEl);
 }