body{margin:0;background:#2c3e50;display:flex;justify-content:center;align-items:center;height:100vh;font-family:Segoe UI,sans-serif}#app{text-align:center;color:#fff;display:flex;flex-direction:column;align-items:center;gap:15px}#header{display:flex;gap:30px;font-size:18px;font-weight:600}canvas{border:3px solid #ecf0f1;border-radius:4px;cursor:pointer}#restart{padding:10px 30px;border:none;border-radius:4px;font-size:16px;font-weight:600;cursor:pointer;background:#3498db;color:#fff;transition:background .2s ease}#restart:hover{background:#2980b9}