def box_strings(*strings: str, width: int = 80) -> str:
    """Centre-align and visually box some strings.

    Args:
        *strings (str): Strings to box. Each string will be printed on its own
            line. You need to ensure the strings are short enough to fit in the
            box (width-6) or the results will not be as intended.
        width (int, optional): Width of the box. Defaults to 80.

    Returns:
        str: The strings, centred and surrounded by a border box.
    """
    lines = ["+" + "-"*(width-2) + "+", "|" + " "*(width-2) + "|"]
    lines.extend(f'|  {string.center(width-6)}  |' for string in strings)
    lines.extend(lines[:2][::-1])
    return "\n".join(lines)