body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #f0f8ff;
  }
  
  .game-container {
    text-align: center;
    background: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
  }
  
  input {
    width: 220px;
    font-size: 22px;
    padding: 10px;
    text-align: center;
    margin-bottom: 20px;
  }
  
  .keypad {
    display: grid;
    grid-template-columns: repeat(3, 70px);
    grid-gap: 10px;
    justify-content: center;
  }
  
  .keypad button {
    padding: 15px;
    font-size: 18px;
    cursor: pointer;
  }
  
  #result {
    margin: 15px 0;
    font-size: 22px;
    font-weight: bold;
  }