https://www.caniemail.com/features/css-column-count/
Can I email… column-count
Supported in Apple Mail. Partially supported in Gmail, Outlook. Not supported in Yahoo! Mail.
column count
https://chriskirknielsen.com/blog/css-grid-with-a-preferred-column-count/
CSS Grid with a preferred column count | chriskirknielsen
Set up a CSS grid with a specific ideal number of columns.
css gridcolumn countpreferred