body {
      
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
      
    }

    .calculator {
      background: #fff;
      padding: 20px;
      border-radius: 15px;
      box-shadow: 0px 4px 15px rgba(0,0,0,0.2);
      width: 350px;
      text-align: center;
    }

    h2 {
      margin-bottom: 15px;
      color: #333;
    }

    input[type="number"] {
      width: 140px;
      padding: 10px;
      margin: 5px;
      border: 1px solid #ccc;
      border-radius: 8px;
      font-size: 16px;
    }

    .buttons {
      margin-top: 15px;
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
    }

    button {
      padding: 12px;
      font-size: 16px;
      border: none;
      border-radius: 8px;
      background: orchid;
      color: white;
      cursor: pointer;
      transition: background 0.3s ease;
    }
    button:hover {
      background: purple;
    }

    .result {
      margin-top: 20px;
      font-size: 18px;
      color: #222;
      font-weight: bold;
      background: #f1f1f1;
      padding: 10px;
      border-radius: 8px;
    }