Adding padding (responsive) to my single posts

Hi there!

I would like to add some padding for my content area in my single posts. I tried doing this >> .single-post .entry-content { padding-left: 20px; padding-right: 20px; }

But the problem is that it is not responsive. I only want to add padding to larger size screens (like laptops) Anything smaller than that, for example iPad for phone size, I want to keep the original padding.

The page I need help with: [log in to see the link]