body {
  font-family: Arial, sans-serif;
  background: #f0f0f0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}
.container {
  text-align: center;
}
.die {
  font-size: 5rem;
  margin: 20px auto;
  width: 120px;
  height: 120px;
  line-height: 120px;
  border: 4px solid #333;
  border-radius: 12px;
  background: #fff;
  color: #333;
}
.roll-btn {
  padding: 10px 20px;
  font-size: 1.2rem;
  background: #4caf50;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s;
}
.roll-btn:hover { background: #45a049; }
.roll-btn:active { background: #388e3c; }