body {
  background: #0b0b0b;
  color: #fff;
  font-family: 'Segoe UI', sans-serif;
  text-align: center;
  margin: 0;
  padding: 0;
}
.container {
  margin: 60px auto;
  max-width: 800px;
}
.balance {
  color: gold;
  margin-bottom: 15px;
  font-size: 18px;
}
.controls input, .controls button {
  padding: 10px 15px;
  margin: 5px;
  font-size: 16px;
  border-radius: 5px;
  border: none;
}
#startBtn { background: #28a745; color: white; }
#cashoutBtn { background: #dc3545; color: white; }
canvas {
  border: 1px solid #333;
  background: #111;
  margin-top: 20px;
}
.multiplier {
  font-size: 48px;
  font-weight: bold;
  margin-top: 20px;
  color: lime;
}