
  <style>
    body {
      font-family: Arial, sans-serif;
      background: #f4f4f4;
      padding: 20px;
    }
    .calculator {
      background: #fff;
      padding: 20px;
      max-width: 400px;
      margin: auto;
      border-radius: 8px;
      box-shadow: 0 0 10px rgba(0,0,0,0.1);
    }
    .calculator h2 {
      text-align: center;
      margin-bottom: 20px;
    }
    .calculator label {
      display: block;
      margin: 10px 0 5px;
    }
    .calculator input {
      width: 100%;
      padding: 8px;
      margin-bottom: 10px;
    }
    .calculator button {
      width: 100%;
      padding: 10px;
      background: #007C7C;
      color: white;
      border: none;
      border-radius: 5px;
      cursor: pointer;
    }
    .result {
      margin-top: 20px;
      font-weight: bold;
      text-align: center;
    }
</style>