:root{--grid-bg: #bbada0;--empty-cell: #cdc1b4}body{margin:0;padding:20px;font-family:Arial,sans-serif;display:flex;flex-direction:column;align-items:center;background-color:#faf8ef}.header{width:100%;max-width:500px;display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.score-container{background:var(--grid-bg);padding:10px 20px;border-radius:5px;color:#fff;text-align:center}.controls{display:flex;gap:10px}#restart-btn{padding:10px;border-radius:5px;border:none;background:var(--grid-bg);color:#fff;cursor:pointer;font-size:16px}#game-container{width:100%;max-width:500px;aspect-ratio:1;background:var(--grid-bg);padding:10px;border-radius:5px;position:relative}.game-grid{display:grid;grid-template-columns:repeat(4,1fr);grid-gap:10px;width:100%;height:100%}.grid-cell{background:var(--empty-cell);border-radius:5px}#game-over,#win-message{display:none;position:absolute;top:0;left:0;right:0;bottom:0;background:#eee4daba;align-items:center;justify-content:center;font-size:48px;font-weight:700;color:#776e65}.back-btn{text-decoration:none;color:#776e65;font-size:24px;font-weight:700;padding:5px 10px;border-radius:5px;transition:background-color .2s}.back-btn:hover{background-color:var(--empty-cell)}.header-left{display:flex;align-items:center;gap:10px}