body {
      font-family: Arial, sans-serif;
      background: #f4f6f9;
      display: flex;
      flex-direction: column; /* để xếp form theo chiều dọc */
      justify-content: flex-start;
      align-items: center;
      gap: 30px; /* khoảng cách giữa 2 form */
      padding: 30px;
    }

    .form-container {
      width: 800px;
      background: #fff;
      border-radius: 8px;
      box-shadow: 0 4px 10px rgba(0,0,0,0.1);
      overflow: hidden;
    }

    .form-header {
      background: #3b6ea5;
      color: #fff;
      padding: 15px;
      font-size: 18px;
      font-weight: bold;
    }

    form {
      padding: 20px;
    }

    label {
      display: block;
      margin-bottom: 6px;
      font-weight: bold;
      font-size: 14px;
    }

    input, select, textarea {
      width: 100%;
      padding: 8px;
      margin-bottom: 15px;
      border: 1px solid #ccc;
      border-radius: 4px;
      font-size: 14px;
    }

    .buttons {
      display: flex;
      justify-content: flex-end;
      gap: 10px;
    }

    .btn {
      padding: 8px 15px;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-weight: bold;
      font-size: 14px;
    }

    .btn-save {
      background: #3b6ea5;
      color: #fff;
    }

    .btn-cancel {
      background: #ccc;
      color: #000;
    }

    .btn:hover {
      opacity: 0.9;
    }

    .package-dimensions {
      display: flex;
      gap: 10px;
    }

    .package-dimensions input {
      flex: 1;
    }