.container {
    max-width: 400px;
    margin: 50px auto;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
  }
  
  h1 {
    text-align: center;
    margin-bottom: 20px;
  }
  
  .section {
    margin-bottom: 15px;
  }
  
  label {
    display: block;
    margin-bottom: 5px;
  }
  
  input[type="number"],
  select {
    width: 100%;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-sizing: border-box;
    margin-bottom: 10px;
  }
  
  button {
    width: 100%;
    padding: 10px;
    background-color: #4caf50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
  }
  
  button:hover {
    background-color: #45a049;
  }
  
  #totalTip {
    margin-top: 20px;
    text-align: center;
    font-size: 18px;
    font-weight: bold;
  }