def get_html_header() -> str:
    """Helper to get a HTML header with some CSS styles for tables.""

    Returns:
        A HTML header as string.
    """
    return """<head>
                <style>
                  table {
                    font-family: arial, sans-serif;
                    border-collapse: collapse;
                    width: 768px
                  }
                  td, th {
                    border: 1px solid #999999;
                    text-align: left;
                    padding: 8px;
                  }
                  tr:nth-child(even) {
                    background-color: #dddddd;
                  }
                </style>
              </head>"""