How to make the display of the office file wider?

Hello your previous CCS advise was very helpful.

I have been googling how to change the menu colours, as the black text on my purple background is not very readable. However everything I have tried to change the text colour of the Off-Canvas main menu text to white did not work.

Would you know what custom CSS I would need to change all menu items to white text (including submenus).
Probably need background colour to not be white when hovering over submenus

Any help you can provide would be gratefully appreciated (or a pointer to some useful help).

Thank you

see

https://siteupdate.vedicmaths.org/index.php

Currently in process of upgrading my version of Joomla for my site upgrade domain

InPre-Update Check for Joomla ‎5.4.4

for Off-Canvas it says

Joomla cannot detect the extension's compatibility with the target version of Joomla.

have you implemented the compatibility stuff for Joomla to upgrade extensions correctly ?

OK getting back to looking at my website

Have got two off canvas menus working (1. for tools and 2. for main menu)

However I can only get the Main menu to display the first level of menu items.

Have you any suggestions for getting the sub menu items to display ?
N.B. the menu item with sub menu items does display a down arrow, but trying to click on it only display the item at the main menu level.

see

https://siteupdate.vedicmaths.org/index.php

If you want to see where I have currently got to

Is it possible to embed the contents of a text file stored in a subdirectory of the webserver ?

Hello, it doesn't seem to work, there are more the 4000 k2 articles and like a 120 are imported.
What is wrong?
That imported page keeps on saying this, but nothing further is happening...