body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #333;
    color: #fff;
  }
  
  .excel-container {
    width: 80%;
    max-width: 800px;
    background-color: #444;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
  }
  
  table {
    border-collapse: collapse;
    width: 100%;
  }
  
  th, td {
    border: 1px solid #555;
    padding: 8px;
    text-align: center;
  }
  
  th {
    background-color: #666;
  }
  
  th:first-child, td:first-child {
    text-align: left;
    font-weight: bold;
  }
  
  .functions {
    margin-top: 20px;
    text-align: center;
  }
  
  .functions button {
    padding: 10px 20px;
    margin: 0 5px;
    background-color: #555;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
  }
  
  .functions button:hover {
    background-color: #777;
  }
  
  #result {
    margin-top: 20px;
    font-weight: bold;
  }
  
  .export button {
    padding: 10px 20px;
    margin: 0 5px;
    background-color: #555;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
  }

  .import button {
    padding: 10px 20px;
    margin: 0 5px;
    background-color: #555;
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
  }