Markdown default code block style is wrong for dark mode

[FeodorFitsner]

The following program produces unreadable code block:

import flet as ft

def main(page: ft.Page):

    page.theme_mode = ft.ThemeMode.DARK

    md = ft.Markdown(
        """
# Hello

This is markdown

    This is a code block

Some more text.
    """
    )
    page.add(md)

ft.app(target=main)