/* bai4.css */
    body {
      font-family: Arial;
      padding: 20px;
    }
    table {
      border-collapse: collapse;
      margin: auto;
      border: 1px solid #ccc;
    }
    td {
      padding: 8px;
    }
    h2 {
      text-align: center;
    }
    select, input[type="date"] {
      width: 200px;
    }
    button {
      margin-top: 10px;
      padding: 6px 12px;
    }