body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
  }
  
  .container {
    width: 80%;
    margin: 20px auto;
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
  }
  
  h3 {
    text-align: center;
    color: #333;
  }
  
  label {
    font-weight: bold;
    font-size: 16px;
  }
  
  .input-group {
    margin-bottom: 20px;
  }
  
  select, input[type="number"], button {
    width: 100%;
    padding: 15px;
    font-size: 16px;
    border-radius: 5px;
    border: 1px solid #ccc;
    box-sizing: border-box;
    margin-top: 10px;
  }
  
  button {
    background-color: #007bff;
    color: white;
    border: none;
    cursor: pointer;
  }
  
  button:hover {
    background-color: #0056b3;
  }
  
  #result {
    margin-top: 20px;
    background-color: #d9edf7;
    padding: 10px;
    border-radius: 5px;
    color: #31708f;
  }