Columns within Columns

Hello,
I am trying to display a page with 4 columns (easy) but when viewed on a mobile phone then I can not squeeze two columns onto a screen.

I had hoped to nest columns e.g.
[su_column size=”1/2″]
[su_column size=”1/2″]
Content in col 1
[/su_column]
[su_column size=”1/2″]
Content in col 2
[/su_column]
[/su_column]

Live example : https://cbc.precisioncomputing.co.uk/wp/history/champions-presidents/

Cheers Neil