Need help with mobile css for resizing of cards and site

Hello. I am working on a client site and would love guidance (css) for how to transition from desktop to mobile and to have the following section in mobile lay out the cards with two per row since the content is super limited and the current layout requires too much scrolling. I have some css code already which I thought would help optimize the mobile experience but it doesn't seem to help with this specific issue.

I've attached an image of the desktop version [6 across] and mobile version [1 across]. Does anyone have the CSS code to adjust this? I'd also welcome any additional suggestions with optimizing resizing for mobile (I am relatively new at this). Thank you in advance!

https://hibiscus-dachshund-wk7b.squarespace.com/config/

pw: forumhelp1

Here's the solution:

https://insidethesquare.co/squarespace-tutorials/multi-column-mobile-list

I have one more question since you are already familiar with my website! Do you know the code for how to add a second button to the navigation? I need to create an additional button to drive to a linked password protected page for gated content. Thank you!

Essentially, I would like to turn the Client Portal page into a Button and have it in a different color and next to the Donate button in the header.

Try this:

https://www.ghostplugins.com/steps/9thnk3tg